/* ===== 全局变量 ===== */
:root {
    --primary: #ff6b9d;
    --primary-dark: #c44569;
    --primary-light: #ffb3c6;
    --secondary: #ffd700;
    --dark: #2d3436;
    --gray: #636e72;
    --light: #f8f9fa;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, #ff6b9d 0%, #c44569 100%);
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 20px 60px rgba(255, 107, 157, 0.25);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== 基础样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: var(--light);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== 粒子背景 ===== */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--primary);
    border-radius: 50%;
    opacity: 0.3;
    animation: float-particle 8s ease-in-out infinite;
}

@keyframes float-particle {

    0%,
    100% {
        transform: translateY(0) translateX(0);
        opacity: 0.3;
    }

    50% {
        transform: translateY(-100px) translateX(20px);
        opacity: 0.6;
    }
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: var(--transition);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--primary);
    text-decoration: none;
    font-family: 'Ma Shan Zheng', cursive;
    letter-spacing: 2px;
}

.nav-logo i {
    font-size: 1.6rem;
    animation: heartbeat-icon 1.5s ease-in-out infinite;
}

@keyframes heartbeat-icon {

    0%,
    100% {
        transform: scale(1);
    }

    14% {
        transform: scale(1.1);
    }

    28% {
        transform: scale(1);
    }

    42% {
        transform: scale(1.15);
    }

    70% {
        transform: scale(1);
    }
}

.nav-menu {
    display: flex;
    gap: 35px;
    list-style: none;
}

.nav-link {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 10px 0;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    padding: 10px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--dark);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
}

/* ===== 信封样式 ===== */

.envelope-section {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: 100px 20px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #fff5f7 0%, #fff0f3 30%, #ffdee9 60%, #ffc2d1 100%);
    z-index: 0;
    pointer-events: none;
}

/* 背景装饰心形 */
.hero-bg::before {
    content: '';
    position: absolute;
    top: 10%;
    left: 10%;
    width: 60px;
    height: 60px;
    background: radial-gradient(circle, rgba(255, 107, 157, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float-heart 6s ease-in-out infinite;
    pointer-events: none;
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: 20%;
    right: 15%;
    width: 80px;
    height: 80px;
    background: radial-gradient(circle, rgba(255, 107, 157, 0.12) 0%, transparent 70%);
    border-radius: 50%;
    animation: float-heart 8s ease-in-out infinite 2s;
    pointer-events: none;
}

/* 背景小星星装饰 */
.hero-bg .star {
    position: absolute;
    width: 8px;
    height: 8px;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 50%;
    animation: twinkle 3s ease-in-out infinite;
    pointer-events: none;
}

.hero-bg .star:nth-child(1) {
    top: 15%;
    left: 25%;
    animation-delay: 0s;
}

.hero-bg .star:nth-child(2) {
    top: 25%;
    right: 20%;
    animation-delay: 0.5s;
}

.hero-bg .star:nth-child(3) {
    top: 40%;
    left: 15%;
    animation-delay: 1s;
}

.hero-bg .star:nth-child(4) {
    bottom: 35%;
    right: 25%;
    animation-delay: 1.5s;
}

.hero-bg .star:nth-child(5) {
    top: 60%;
    left: 30%;
    animation-delay: 2s;
}

.hero-bg .star:nth-child(6) {
    bottom: 25%;
    left: 20%;
    animation-delay: 2.5s;
}

@keyframes twinkle {

    0%,
    100% {
        opacity: 0.3;
        transform: scale(1);
    }

    50% {
        opacity: 1;
        transform: scale(1.3);
    }
}

@keyframes float-heart {

    0%,
    100% {
        transform: translateY(0) scale(1);
        opacity: 0.6;
    }

    50% {
        transform: translateY(-20px) scale(1.1);
        opacity: 0.8;
    }
}

.envelope-container {
    position: relative;
    z-index: 5;
}

.envelope {
    position: relative;
    width: 580px;
    height: 400px;
    z-index: 10;
    cursor: pointer;
    perspective: 1500px;
    transform-style: preserve-3d;
}

/* 信封左侧 */
.envelope-left {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(135deg,
            #fff0f3 0%,
            #ffdee9 15%,
            #ffc2d1 30%,
            #ffb3c6 45%,
            #ff8fab 60%,
            #ff6b9d 80%,
            #c44569 100%);
    clip-path: polygon(0 0, 100% 47%, 100% 100%, 0 100%);
    z-index: 1;
    border-radius: 0 0 0 22px;
    box-shadow:
        inset -15px 0 40px rgba(0, 0, 0, 0.08),
        inset 0 -10px 25px rgba(0, 0, 0, 0.06),
        inset 0 15px 30px rgba(255, 255, 255, 0.12);
}

/* 信封左侧装饰线 */
.envelope-left::before {
    content: '';
    position: absolute;
    top: 30%;
    right: 5%;
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.4) 0%, transparent 100%);
    pointer-events: none;
}

/* 信封左侧小星星装饰 */
.envelope-left .star-1 {
    position: absolute;
    top: 25%;
    left: 15%;
    width: 10px;
    height: 10px;
    background: rgba(255, 255, 255, 0.7);
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 2s ease-in-out infinite;
    pointer-events: none;
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.8);
}

.envelope-left .star-2 {
    position: absolute;
    top: 65%;
    left: 10%;
    width: 7px;
    height: 7px;
    background: rgba(255, 255, 255, 0.55);
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 2.5s ease-in-out infinite 0.5s;
    pointer-events: none;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.6);
}

/* 信封左侧浮动心形 */
.envelope-left .floating-heart.fh-1 {
    position: absolute;
    top: 40%;
    left: 25%;
    font-size: 16px;
    color: rgba(255, 255, 255, 0.4);
    animation: float-heart 4s ease-in-out infinite;
    pointer-events: none;
    text-shadow: 0 0 10px rgba(255, 107, 157, 0.6);
}

/* 信封左侧心形轨迹装饰 */
.envelope-left .heart-trails {
    position: absolute;
    width: 60px;
    height: 60px;
    pointer-events: none;
}

.envelope-left .heart-trails.ht-1 {
    top: 25%;
    left: 15%;
    background: radial-gradient(circle at 30% 30%, rgba(255, 182, 197, 0.15) 0%, transparent 50%);
    animation: trail-float 5s ease-in-out infinite;
}

.envelope-left .heart-trails.ht-2 {
    top: 60%;
    left: 8%;
    width: 40px;
    height: 40px;
    background: radial-gradient(circle at 70% 70%, rgba(255, 182, 197, 0.12) 0%, transparent 50%);
    animation: trail-float 4.5s ease-in-out infinite 1.5s;
}

@keyframes sparkle {

    0%,
    100% {
        opacity: 0.3;
        transform: rotate(-45deg) scale(1);
        text-shadow: 0 0 10px rgba(255, 107, 157, 0.5);
    }

    50% {
        opacity: 0.7;
        transform: rotate(-45deg) scale(1.3);
        text-shadow: 0 0 20px rgba(255, 107, 157, 0.8), 0 0 30px rgba(255, 182, 197, 0.6);
    }
}

@keyframes twinkle {

    0%,
    100% {
        opacity: 0.3;
        transform: scale(1) rotate(0deg);
    }

    50% {
        opacity: 0.8;
        transform: scale(1.2) rotate(180deg);
    }
}

@keyframes float-heart {

    0%,
    100% {
        opacity: 0.3;
        transform: translateY(0) scale(1);
    }

    25% {
        opacity: 0.5;
        transform: translateY(-8px) scale(1.1);
    }

    50% {
        opacity: 0.4;
        transform: translateY(-4px) scale(1);
    }

    75% {
        opacity: 0.5;
        transform: translateY(-12px) scale(1.05);
    }
}

@keyframes mini-float {

    0%,
    100% {
        opacity: 0.2;
        transform: translateY(0) scale(1);
    }

    50% {
        opacity: 0.4;
        transform: translateY(-5px) scale(1.1);
    }
}

@keyframes chain-float {

    0%,
    100% {
        opacity: 0.15;
        transform: translateY(0) rotate(0deg);
    }

    50% {
        opacity: 0.25;
        transform: translateY(-6px) rotate(5deg);
    }
}

@keyframes trail-float {

    0%,
    100% {
        opacity: 0.1;
        transform: translateY(0) scale(1);
    }

    50% {
        opacity: 0.18;
        transform: translateY(-8px) scale(1.1);
    }
}

/* 信封右侧心形轨迹装饰 */
.envelope-right .heart-trails {
    position: absolute;
    width: 50px;
    height: 50px;
    pointer-events: none;
}

.envelope-right .heart-trails.ht-3 {
    top: 30%;
    right: 18%;
    background: radial-gradient(circle at 70% 30%, rgba(255, 182, 197, 0.14) 0%, transparent 50%);
    animation: trail-float 4.8s ease-in-out infinite 0.8s;
}

.envelope-right .heart-trails.ht-4 {
    top: 65%;
    right: 12%;
    width: 35px;
    height: 35px;
    background: radial-gradient(circle at 30% 70%, rgba(255, 182, 197, 0.1) 0%, transparent 50%);
    animation: trail-float 5.2s ease-in-out infinite 2s;
}

/* 信封右侧 */
.envelope-right {
    position: absolute;
    bottom: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(225deg,
            #fff0f3 0%,
            #ffdee9 15%,
            #ffc2d1 30%,
            #ffb3c6 45%,
            #ff8fab 60%,
            #ff6b9d 80%,
            #c44569 100%);
    clip-path: polygon(0 47%, 100% 0, 100% 100%, 0 100%);
    z-index: 1;
    border-radius: 0 0 22px 0;
    box-shadow:
        inset 15px 0 40px rgba(0, 0, 0, 0.08),
        inset 0 -10px 25px rgba(0, 0, 0, 0.06),
        inset 0 15px 30px rgba(255, 255, 255, 0.12);
}

/* 信封右侧装饰线 */
.envelope-right::before {
    content: '';
    position: absolute;
    top: 30%;
    left: 5%;
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.4) 100%);
    pointer-events: none;
}

/* 信封右侧小星星装饰 */
.envelope-right .star-3 {
    position: absolute;
    top: 30%;
    right: 12%;
    width: 9px;
    height: 9px;
    background: rgba(255, 255, 255, 0.65);
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 2.2s ease-in-out infinite 0.3s;
    pointer-events: none;
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.7);
}

.envelope-right .star-4 {
    position: absolute;
    top: 70%;
    right: 18%;
    width: 6px;
    height: 6px;
    background: rgba(255, 255, 255, 0.5);
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 2.8s ease-in-out infinite 1s;
    pointer-events: none;
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.5);
}

/* 信封右侧浮动心形 */
.envelope-right .floating-heart.fh-2 {
    position: absolute;
    top: 45%;
    right: 28%;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.35);
    animation: float-heart 4.5s ease-in-out infinite 1.5s;
    pointer-events: none;
    text-shadow: 0 0 8px rgba(255, 107, 157, 0.5);
}

/* 信封右侧小星星3 */
.envelope-right .star-6 {
    position: absolute;
    top: 50%;
    right: 10%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.4);
    clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
    animation: twinkle 2.8s ease-in-out infinite 0.6s;
    pointer-events: none;
    box-shadow: 0 0 5px rgba(255, 255, 255, 0.35);
}

/* 信封右侧小心形 */
.envelope-right .small-heart.sh-3 {
    position: absolute;
    top: 35%;
    right: 32%;
    font-size: 9px;
    color: rgba(255, 255, 255, 0.22);
    animation: mini-float 3.2s ease-in-out infinite 0.5s;
    pointer-events: none;
}

.envelope-right .small-heart.sh-4 {
    position: absolute;
    top: 75%;
    right: 25%;
    font-size: 7px;
    color: rgba(255, 255, 255, 0.18);
    animation: mini-float 3.8s ease-in-out infinite 1.3s;
    pointer-events: none;
}

/* 信封右侧丝带装饰 */
.envelope-right .ribbon-right {
    position: absolute;
    top: 15%;
    right: -5%;
    width: 30px;
    height: 80px;
    background: linear-gradient(225deg, rgba(255, 182, 197, 0.6) 0%, rgba(255, 107, 157, 0.8) 100%);
    clip-path: polygon(0 0, 0 30%, 30% 40%, 0 50%, 0 100%, 100% 100%, 100% 0);
    transform: rotate(15deg);
    pointer-events: none;
    box-shadow: -2px 2px 10px rgba(0, 0, 0, 0.15);
}

/* 信封底部 */
.envelope-bottom {
    position: absolute;
    bottom: 0;
    left: 2.5%;
    width: 95%;
    height: 53%;
    background: linear-gradient(180deg,
            #ff8fab 0%,
            #ff6b9d 20%,
            #c44569 60%,
            #a8325a 90%,
            #8b2a4a 100%);
    border-radius: 0 0 25px 25px;
    z-index: 0;
    box-shadow:
        0 30px 80px rgba(255, 107, 157, 0.4),
        0 15px 40px rgba(0, 0, 0, 0.22),
        inset 0 5px 15px rgba(255, 255, 255, 0.08);
    overflow: hidden;
}

/* 信封底部装饰条纹 */
.envelope-bottom::before {
    content: '';
    position: absolute;
    top: 8%;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg,
            transparent 5%,
            rgba(255, 255, 255, 0.1) 20%,
            rgba(255, 255, 255, 0.2) 50%,
            rgba(255, 255, 255, 0.1) 80%,
            transparent 95%);
}

/* 信封底部心形水印 */
.envelope-bottom::after {
    content: '';
    position: absolute;
    bottom: 15%;
    left: 50%;
    transform: translateX(-50%);
    width: 40%;
    height: 30%;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M50,10 C70,10 85,25 85,45 C85,70 65,85 50,95 C35,85 15,70 15,45 C15,25 30,10 50,10' fill='rgba(255,255,255,0.04)'/%3E%3C/svg%3E");
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

/* 信封底部纹理 */
.envelope-bottom .bottom-texture {
    position: absolute;
    top: 15%;
    left: 8%;
    right: 8%;
    height: 60%;
    background: linear-gradient(90deg,
            rgba(255, 255, 255, 0.03) 0%,
            rgba(255, 255, 255, 0.08) 50%,
            rgba(255, 255, 255, 0.03) 100%);
    border-radius: 10px;
    pointer-events: none;
}

/* 信封底部装饰图案 */
.envelope-bottom .bottom-pattern {
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translateX(-50%);
    width: 70%;
    height: 50%;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.05) 2%, transparent 2%),
        radial-gradient(circle at 80% 70%, rgba(255, 255, 255, 0.05) 2%, transparent 2%),
        radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.03) 3%, transparent 3%),
        radial-gradient(circle at 30% 70%, rgba(255, 255, 255, 0.04) 2%, transparent 2%),
        radial-gradient(circle at 70% 30%, rgba(255, 255, 255, 0.04) 2%, transparent 2%);
    pointer-events: none;
}

/* 信封底部边框装饰 */
.envelope-bottom .bottom-border {
    position: absolute;
    top: 5%;
    left: 5%;
    right: 5%;
    bottom: 5%;
    border: 1px dashed rgba(255, 255, 255, 0.15);
    border-radius: 15px;
    pointer-events: none;
}

/* 信封底部心形链 */
.envelope-bottom .heart-chain {
    position: absolute;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.18);
    animation: chain-float 4s ease-in-out infinite;
    pointer-events: none;
}

.envelope-bottom .heart-chain.hc-1 {
    left: 15%;
    bottom: 20%;
    animation-delay: 0s;
}

.envelope-bottom .heart-chain.hc-2 {
    left: 50%;
    transform: translateX(-50%);
    bottom: 18%;
    animation-delay: 1s;
}

.envelope-bottom .heart-chain.hc-3 {
    right: 15%;
    bottom: 20%;
    animation-delay: 2s;
}

/* 信封盖 */
.envelope-flap {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 56%;
    background: linear-gradient(180deg,
            #fff5f7 0%,
            #ffd6e0 10%,
            #ffc2d1 25%,
            #ffb3c6 40%,
            #ff8fab 55%,
            #ff6b9d 75%,
            #c44569 100%);
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    transform-origin: top center;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        box-shadow 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 4;
    box-shadow:
        0 -12px 40px rgba(255, 255, 255, 0.45),
        0 12px 35px rgba(0, 0, 0, 0.15),
        inset 0 8px 25px rgba(255, 255, 255, 0.35),
        inset 0 -5px 15px rgba(0, 0, 0, 0.05);
}

/* 信封盖外层光泽 */
.envelope-flap::before {
    content: '';
    position: absolute;
    top: 3%;
    left: 10%;
    right: 10%;
    height: 40%;
    background: linear-gradient(180deg,
            rgba(255, 255, 255, 0.6) 0%,
            rgba(255, 255, 255, 0.2) 50%,
            transparent 100%);
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    border-radius: 0 0 50% 50%;
    pointer-events: none;
}

/* 信封盖内侧光泽 */
.envelope-flap::after {
    content: '';
    position: absolute;
    top: 5%;
    left: 5%;
    right: 5%;
    bottom: 5%;
    background: linear-gradient(180deg,
            rgba(255, 255, 255, 0.1) 0%,
            transparent 40%,
            rgba(0, 0, 0, 0.05) 80%,
            rgba(0, 0, 0, 0.1) 100%);
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    pointer-events: none;
}

/* 信封盖中心装饰 */
.envelope-flap .flap-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    pointer-events: none;
}

.envelope-flap .flap-center::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    border: 2px solid rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    animation: pulse-border 3s ease-in-out infinite;
}

.envelope-flap .flap-center::after {
    content: '♥';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 24px;
    color: rgba(255, 255, 255, 0.5);
    animation: heartbeat 1.5s ease-in-out infinite;
    text-shadow: 0 0 15px rgba(255, 107, 157, 0.6);
}

@keyframes pulse-border {

    0%,
    100% {
        opacity: 0.3;
        transform: translate(-50%, -50%) scale(1);
    }

    50% {
        opacity: 0.6;
        transform: translate(-50%, -50%) scale(1.1);
    }
}

@keyframes heartbeat {

    0%,
    100% {
        transform: translate(-50%, -50%) scale(1);
    }

    14% {
        transform: translate(-50%, -50%) scale(1.1);
    }

    28% {
        transform: translate(-50%, -50%) scale(1);
    }

    42% {
        transform: translate(-50%, -50%) scale(1.15);
    }

    70% {
        transform: translate(-50%, -50%) scale(1);
    }
}

/* 信封盖中心装饰 */
.envelope-flap .flap-center {
    position: absolute;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80px;
    height: 80px;
    pointer-events: none;
}

.envelope-flap .center-heart {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 28px;
    color: rgba(255, 255, 255, 0.6);
    animation: heartbeat 1.5s ease-in-out infinite;
    text-shadow:
        0 0 20px rgba(255, 107, 157, 0.8),
        0 0 40px rgba(255, 182, 197, 0.6),
        0 0 60px rgba(255, 218, 226, 0.4);
}

.envelope-flap .pulse-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.3);
    animation: pulse-ring 3s ease-out infinite;
}

.envelope-flap .pulse-ring.ring-1 {
    width: 60px;
    height: 60px;
}

.envelope-flap .pulse-ring.ring-2 {
    width: 60px;
    height: 60px;
    animation-delay: 1.5s;
}

@keyframes pulse-ring {
    0% {
        opacity: 0.6;
        transform: translate(-50%, -50%) scale(0.8);
    }

    100% {
        opacity: 0;
        transform: translate(-50%, -50%) scale(1.8);
    }
}

/* 信封盖装饰框架 */
.envelope-flap .flap-frame {
    position: absolute;
    top: 6%;
    left: 8%;
    right: 8%;
    bottom: 12%;
    border: 1px solid rgba(255, 255, 255, 0.15);
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    pointer-events: none;
}

/* 信封盖角落装饰 */
.envelope-flap .flap-corner {
    position: absolute;
    width: 20px;
    height: 20px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    pointer-events: none;
}

.envelope-flap .flap-corner.tl {
    top: 8%;
    left: 10%;
    border-right: none;
    border-bottom: none;
}

.envelope-flap .flap-corner.tr {
    top: 8%;
    right: 10%;
    border-left: none;
    border-bottom: none;
}

.envelope-flap .flap-corner.bl {
    bottom: 15%;
    left: 15%;
    border-right: none;
    border-top: none;
}

.envelope-flap .flap-corner.br {
    bottom: 15%;
    right: 15%;
    border-left: none;
    border-top: none;
}

/* 信封装饰丝带 */
.envelope-ribbon {
    position: absolute;
    top: 38%;
    left: 0;
    right: 0;
    z-index: 15;
    pointer-events: none;
}

.envelope-ribbon .ribbon-main {
    position: absolute;
    top: 50%;
    left: 3%;
    right: 3%;
    height: 14px;
    background: linear-gradient(90deg,
            #ffc0cb 0%,
            #ff69b4 20%,
            #db7093 50%,
            #ff69b4 80%,
            #ffc0cb 100%);
    transform: translateY(-50%);
    border-radius: 2px;
    box-shadow:
        0 2px 8px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.4);
}

.envelope-ribbon .ribbon-bow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 45px;
    height: 40px;
}

.envelope-ribbon .bow-left,
.envelope-ribbon .bow-right {
    position: absolute;
    top: 20%;
    width: 16px;
    height: 16px;
    background: linear-gradient(135deg, #ff69b4 0%, #db7093 100%);
    border-radius: 50%;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.envelope-ribbon .bow-left {
    left: 0;
}

.envelope-ribbon .bow-right {
    right: 0;
}

.envelope-ribbon .bow-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 10px;
    height: 10px;
    background: #db7093;
    border-radius: 50%;
    box-shadow:
        0 1px 4px rgba(0, 0, 0, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

/* 信封盖装饰条纹 */
.envelope-flap .flap-stripes {
    position: absolute;
    top: 18%;
    left: 0;
    right: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    pointer-events: none;
}

.envelope-flap .flap-stripes .stripe {
    width: 60%;
    height: 3px;
    background: linear-gradient(90deg,
            transparent 0%,
            rgba(255, 255, 255, 0.25) 20%,
            rgba(255, 255, 255, 0.4) 50%,
            rgba(255, 255, 255, 0.25) 80%,
            transparent 100%);
    border-radius: 2px;
}

.envelope-flap .flap-stripes .stripe.s1 {
    width: 55%;
    opacity: 0.9;
}

.envelope-flap .flap-stripes .stripe.s2 {
    width: 50%;
    opacity: 0.7;
}

.envelope-flap .flap-stripes .stripe.s3 {
    width: 45%;
    opacity: 0.5;
}

/* 信封盖角落装饰 */
.envelope-flap .corner-decoration {
    position: absolute;
    width: 25px;
    height: 25px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    pointer-events: none;
}

.envelope-flap .corner-decoration.top-left {
    top: 8%;
    left: 12%;
    border-right: none;
    border-bottom: none;
    border-radius: 4px 0 0 0;
}

.envelope-flap .corner-decoration.top-right {
    top: 8%;
    right: 12%;
    border-left: none;
    border-bottom: none;
    border-radius: 0 4px 0 0;
}

.envelope-flap .corner-decoration.bottom-left {
    bottom: 15%;
    left: 18%;
    border-right: none;
    border-top: none;
    border-radius: 0 0 0 4px;
}

.envelope-flap .corner-decoration.bottom-right {
    bottom: 15%;
    right: 18%;
    border-left: none;
    border-top: none;
    border-radius: 0 0 4px 0;
}

/* 信封盖侧边装饰 */
.envelope-flap .side-decoration {
    position: absolute;
    top: 25%;
    width: 2px;
    height: 40%;
    background: linear-gradient(180deg,
            transparent 0%,
            rgba(255, 255, 255, 0.3) 20%,
            rgba(255, 255, 255, 0.2) 80%,
            transparent 100%);
    pointer-events: none;
}

.envelope-flap .side-decoration.left {
    left: 15%;
}

.envelope-flap .side-decoration.right {
    right: 15%;
}

/* 信封盖额外条纹 */
.envelope-flap .flap-stripes .stripe.s4 {
    width: 40%;
    opacity: 0.4;
}

/* 信封盖第三层脉冲环 */
.envelope-flap .pulse-ring.ring-3 {
    width: 60px;
    height: 60px;
    animation-delay: 0.75s;
}

background: linear-gradient(180deg,
    rgba(255, 255, 255, 0.4) 0%,
    rgba(255, 255, 255, 0.15) 40%,
    transparent 70%);
clip-path: polygon(0 0, 100% 0, 50% 100%);
border-radius: 0 0 45% 45%;
pointer-events: none;
}

/* 信封盖纹理装饰 */
.envelope-flap .flap-pattern {
    position: absolute;
    top: 15%;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 30%;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M100,10 Q120,30 100,50 Q80,30 100,10' fill='none' stroke='rgba(255,255,255,0.15)' stroke-width='1.5'/%3E%3Cpath d='M100,25 Q115,40 100,55 Q85,40 100,25' fill='none' stroke='rgba(255,255,255,0.1)' stroke-width='1'/%3E%3Ccircle cx='100' cy='70' r='8' fill='none' stroke='rgba(255,255,255,0.12)' stroke-width='1'/%3E%3C/svg%3E");
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    pointer-events: none;
}

.envelope.open .envelope-flap {
    transform: rotateX(168deg);
    z-index: 0;
    box-shadow:
        0 8px 25px rgba(0, 0, 0, 0.12),
        inset 0 -8px 20px rgba(0, 0, 0, 0.08);
    transition: transform 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        box-shadow 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        opacity 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* 信纸 */
.envelope-paper {
    position: absolute;
    width: 90%;
    height: 80%;
    top: 55%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #ffffff;
    border-radius: 15px;
    box-shadow:
        0 10px 35px rgba(0, 0, 0, 0.06),
        inset 0 0 40px rgba(255, 180, 200, 0.04);
    z-index: 2;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        box-shadow 0.8s cubic-bezier(0.4, 0, 0.2, 1),
        opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
    border: 1px solid rgba(255, 180, 200, 0.15);
}

/* 信纸背景图片 */
.paper-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('letter-image.jpg');
    background-size: cover;
    background-position: center center;
    opacity: 0;
    z-index: 0;
    transition: opacity 1s ease;
}

.envelope.open .paper-background {
    opacity: 0.85;
}

/* 信纸纹理 */
.envelope-paper::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
    pointer-events: none;
}

.envelope.open .envelope-paper {
    transform: translate(-50%, -55%) scale(1.05);
    z-index: 100;
    box-shadow:
        0 40px 100px rgba(255, 107, 157, 0.32),
        0 20px 50px rgba(0, 0, 0, 0.18),
        inset 0 0 50px rgba(255, 180, 200, 0.05);
    transition: transform 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        box-shadow 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        opacity 0.85s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* 信纸内容 */
.paper-content {
    padding: 25px 25px;
    height: 100%;
    display: flex;
    position: relative;
    z-index: 1;
    background: linear-gradient(180deg,
            rgba(255, 254, 249, 0.55) 0%,
            rgba(255, 255, 255, 0.5) 50%,
            rgba(255, 245, 247, 0.55) 100%);
    backdrop-filter: blur(1px);
    flex-direction: column;
    opacity: 0;
    transform: translateY(25px);
    transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
        transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
    overflow-y: auto;
    justify-content: center;
    align-items: center;
    text-align: center;
    box-sizing: border-box;
}

.envelope.open .paper-content {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) 0.25s,
        transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) 0.25s;
}

/* 信头 */
.letter-header {
    text-align: center;
    margin-bottom: 12px;
    padding-bottom: 8px;
    width: 100%;
}

.letter-date {
    font-family: 'Noto Serif SC', serif;
    font-size: 0.75rem;
    color: #888;
    margin-bottom: 4px;
    font-weight: 400;
    letter-spacing: 1px;
}

.letter-to {
    font-family: 'ZCOOL XiaoWei', 'Ma Shan Zheng', cursive;
    font-size: 1.4rem;
    color: #c44569;
    letter-spacing: 4px;
    text-shadow: 0 2px 10px rgba(196, 69, 105, 0.25);
    font-weight: normal;
}

/* 信内容 */
.letter-body {
    flex: 1;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.letter-body p {
    font-family: 'ZCOOL XiaoWei', 'Noto Serif SC', serif;
    font-size: 1.15rem;
    line-height: 2;
    color: #4a4a4a;
    margin-bottom: 10px;
    font-weight: 400;
    letter-spacing: 2px;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.9);
    opacity: 0.9;
}

.letter-body p:first-child {
    font-family: 'ZCOOL XiaoWei', 'Ma Shan Zheng', cursive;
    font-size: 1.4rem;
    color: #c44569;
    margin-bottom: 12px;
    letter-spacing: 3px;
    text-shadow: 0 0 1px rgba(196, 69, 105, 0.2);
}

/* 信结尾 */
.letter-footer {
    margin-top: auto;
    text-align: center;
    padding-top: 12px;
    width: 100%;
}

.letter-footer p {
    font-family: 'ZCOOL XiaoWei', 'Noto Serif SC', serif;
    font-size: 1rem;
    color: #5a5a5a;
    margin-bottom: 8px;
    line-height: 1.8;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.8);
    letter-spacing: 2px;
}

.letter-signature {
    font-family: 'ZCOOL XiaoWei', cursive;
    font-size: 1.4rem !important;
    color: #c44569 !important;
    margin-top: 10px !important;
    letter-spacing: 3px;
    text-shadow: 0 0 1px rgba(196, 69, 105, 0.3);
}

/* 邮票 */
.letter-stamp {
    position: absolute;
    bottom: 30px;
    left: 35px;
    width: 65px;
    height: 65px;
    background: linear-gradient(135deg, #ffdee9 0%, #ffb3c6 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(255, 107, 157, 0.3);
    border: 2px solid rgba(255, 107, 157, 0.3);
}

.stamp-heart {
    font-size: 2.5rem;
    animation: heartbeat 1.5s ease-in-out infinite;
}

/* 信封封口 - 心形装饰 */
.envelope-seal {
    position: absolute;
    bottom: 5%;
    left: 50%;
    transform: translateX(-50%);
    z-index: 5;
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
        transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.envelope.open .envelope-seal {
    opacity: 0;
    transform: translateX(-50%) scale(0.35) translateY(35px);
    transition: opacity 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.seal-ring {
    width: 85px;
    height: 85px;
    border-radius: 50%;
    background: linear-gradient(135deg,
            #fff8dc 0%,
            #ffd700 15%,
            #ffb347 35%,
            #ff8c00 55%,
            #ff6600 75%,
            #cc5200 90%,
            #a04000 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow:
        0 12px 50px rgba(255, 165, 0, 0.6),
        0 6px 20px rgba(0, 0, 0, 0.22),
        inset 0 6px 25px rgba(255, 255, 255, 0.55),
        inset 0 -5px 18px rgba(255, 100, 0, 0.4);
    cursor: pointer;
    transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 4px solid rgba(255, 255, 255, 0.8);
    position: relative;
}

/* 印章外层光环 */
.seal-ring::before {
    content: '';
    position: absolute;
    top: -8px;
    left: -8px;
    right: -8px;
    bottom: -8px;
    border-radius: 50%;
    border: 2px solid rgba(255, 215, 0, 0.4);
    animation: glow 2s ease-in-out infinite;
    pointer-events: none;
}

@keyframes glow {

    0%,
    100% {
        opacity: 0.4;
        transform: scale(1);
    }

    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

/* 印章高光 */
.seal-ring::after {
    content: '';
    position: absolute;
    top: 8%;
    left: 12%;
    width: 35%;
    height: 35%;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9) 0%, rgba(255, 255, 255, 0.35) 100%);
    border-radius: 50%;
    filter: blur(2px);
}

.seal-ring:hover {
    transform: scale(1.2);
    box-shadow:
        0 18px 60px rgba(255, 165, 0, 0.75),
        0 8px 25px rgba(0, 0, 0, 0.28),
        inset 0 6px 25px rgba(255, 255, 255, 0.6),
        inset 0 -5px 18px rgba(255, 100, 0, 0.45);
}

.seal-icon {
    font-size: 2.6rem;
    color: #fff;
    animation: heartbeat 1.3s ease-in-out infinite;
    text-shadow:
        0 3px 15px rgba(0, 0, 0, 0.4),
        0 0 30px rgba(255, 255, 255, 0.7),
        0 0 50px rgba(255, 215, 0, 0.5);
    position: relative;
    z-index: 1;
}

/* 打开提示 */
.envelope-hint {
    position: absolute;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
        transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 5;
}

.hint-icon {
    font-size: 2.5rem;
    margin-bottom: 10px;
    animation: float 2s ease-in-out infinite;
}

.envelope-hint p {
    font-family: 'Ma Shan Zheng', cursive;
    font-size: 1.3rem;
    color: var(--primary);
    letter-spacing: 4px;
    text-shadow: 0 2px 10px rgba(255, 107, 157, 0.3);
}

.envelope.open .envelope-hint {
    opacity: 0;
    transform: translateX(-50%) translateY(20px);
    transition: opacity 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275),
        transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* 信封控制按钮 */
.envelope-controls {
    position: absolute;
    bottom: 120px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 15px;
    z-index: 100;
}

.control-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: linear-gradient(135deg, #ff6b9d 0%, #ff8fab 50%, #ffb3c6 100%);
    border: none;
    border-radius: 30px;
    color: white;
    font-family: 'Ma Shan Zheng', cursive;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow:
        0 8px 25px rgba(255, 107, 157, 0.4),
        0 4px 15px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.control-btn:hover {
    transform: translateY(-3px);
    box-shadow:
        0 12px 35px rgba(255, 107, 157, 0.5),
        0 6px 20px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.control-btn:active {
    transform: translateY(-1px);
    box-shadow:
        0 6px 20px rgba(255, 107, 157, 0.4),
        0 3px 10px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.control-btn:focus {
    outline: none;
}

.btn-icon {
    font-size: 1.3rem;
    animation: float 2s ease-in-out infinite;
}

.btn-text {
    letter-spacing: 2px;
}

/* 关闭按钮特殊样式 */
.close-btn {
    background: linear-gradient(135deg, #6c757d 0%, #868e96 50%, #adb5bd 100%);
    box-shadow:
        0 8px 25px rgba(108, 117, 125, 0.35),
        0 4px 15px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.close-btn:hover {
    box-shadow:
        0 12px 35px rgba(108, 117, 125, 0.45),
        0 6px 20px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

/* 音乐控制容器 */
.music-controls {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 100;
}

/* 音乐按钮 */
.music-btn {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ff6b9d 0%, #ff8fab 50%, #ffb3c6 100%);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow:
        0 8px 25px rgba(255, 107, 157, 0.4),
        0 4px 15px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.music-btn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow:
        0 12px 35px rgba(255, 107, 157, 0.5),
        0 6px 20px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.music-btn:active {
    transform: translateY(-1px) scale(0.98);
}

.music-btn.playing {
    animation: pulse 2s ease-in-out infinite;
}

.music-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.music-btn.playing .music-icon {
    animation: spin 3s linear infinite;
}

@keyframes pulse {

    0%,
    100% {
        box-shadow:
            0 8px 25px rgba(255, 107, 157, 0.4),
            0 4px 15px rgba(0, 0, 0, 0.1),
            inset 0 1px 0 rgba(255, 255, 255, 0.3);
    }

    50% {
        box-shadow:
            0 12px 35px rgba(255, 107, 157, 0.6),
            0 6px 20px rgba(0, 0, 0, 0.15),
            inset 0 1px 0 rgba(255, 255, 255, 0.3);
    }
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: 50px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s ease-in-out infinite;
}

.scroll-indicator::before {
    content: '';
    width: 20px;
    height: 30px;
    border: 2px solid var(--primary);
    border-radius: 10px;
    display: block;
    position: relative;
}

.scroll-indicator::after {
    content: '';
    width: 4px;
    height: 8px;
    background: var(--primary);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 1.5s ease-in-out infinite;
}

@keyframes scroll {
    0% {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }

    100% {
        transform: translateX(-50%) translateY(12px);
        opacity: 0;
    }
}

@keyframes bounce {

    0%,
    100% {
        transform: translateX(-50%) translateY(0);
    }

    50% {
        transform: translateX(-50%) translateY(10px);
    }
}

/* ===== 故事区域 ===== */
.story {
    padding: 100px 0;
    background: var(--white);
    position: relative;
    z-index: 1;
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-tag {
    font-size: 0.9rem;
    color: var(--primary);
    font-weight: 600;
    letter-spacing: 3px;
    text-transform: uppercase;
    margin-bottom: 15px;
    display: block;
}

.section-title {
    font-family: 'Noto Serif SC', serif;
    font-size: 2.8rem;
    color: var(--dark);
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient);
    border-radius: 2px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--gray);
    margin-top: 30px;
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--primary-light) 0%, var(--primary) 50%, var(--primary-dark) 100%);
    transform: translateX(-50%);
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 80px;
}

.timeline-item.left {
    padding-right: calc(50% + 40px);
    text-align: right;
}

.timeline-item.right {
    padding-left: calc(50% + 40px);
}

.timeline-icon {
    position: absolute;
    top: 0;
    width: 50px;
    height: 50px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: var(--white);
    box-shadow: 0 5px 20px rgba(255, 107, 157, 0.3);
    z-index: 2;
}

.timeline-item.left .timeline-icon {
    right: -25px;
}

.timeline-item.right .timeline-icon {
    left: -25px;
}

.timeline-content {
    background: var(--white);
    padding: 35px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 107, 157, 0.1);
    transition: var(--transition);
}

.timeline-content:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.timeline-item.left .timeline-content {
    margin-right: 30px;
}

.timeline-item.right .timeline-content {
    margin-left: 30px;
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 12px;
    letter-spacing: 2px;
}

.timeline-content h3 {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.5rem;
    color: var(--dark);
    margin-bottom: 15px;
}

.timeline-content p {
    color: var(--gray);
    line-height: 1.8;
    margin-bottom: 20px;
}

.timeline-image {
    overflow: hidden;
    border-radius: 12px;
    margin-top: 15px;
}

.timeline-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.timeline-content:hover .timeline-image img {
    transform: scale(1.05);
}

/* ===== 相册区域 ===== */
.gallery {
    padding: 100px 0;
    background: linear-gradient(180deg, var(--white) 0%, #fff5f7 100%);
    position: relative;
    z-index: 1;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.gallery-item {
    position: relative;
    aspect-ratio: 1;
    overflow: hidden;
    border-radius: 20px;
    cursor: pointer;
}

.gallery-item.wide {
    grid-column: span 2;
    aspect-ratio: 2;
}

.gallery-item.tall {
    grid-row: span 2;
    aspect-ratio: 0.5;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.gallery-item:hover img {
    transform: scale(1.15);
}

.gallery-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(180deg, rgba(255, 107, 157, 0.8) 0%, rgba(196, 69, 105, 0.9) 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.gallery-item:hover .gallery-overlay {
    opacity: 1;
}

.gallery-icon {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
    transform: scale(0);
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.gallery-item:hover .gallery-icon {
    transform: scale(1);
}

.gallery-icon i {
    color: var(--white);
    font-size: 1.3rem;
}

.gallery-caption {
    text-align: center;
    transform: translateY(20px);
    opacity: 0;
    transition: all 0.4s ease;
    transition-delay: 0.1s;
}

.gallery-item:hover .gallery-caption {
    transform: translateY(0);
    opacity: 1;
}

.gallery-caption h4 {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.3rem;
    color: var(--white);
    margin-bottom: 8px;
}

.gallery-caption p {
    color: rgba(255, 255, 255, 0.85);
    font-size: 0.95rem;
}

/* ===== 时光区域 ===== */
.moments {
    padding: 100px 0;
    background: var(--white);
    position: relative;
    z-index: 1;
}

.moments-grid {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.moment-card {
    background: var(--light);
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
    width: 340px;
    flex-shrink: 0;
}

.moment-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: var(--shadow-hover);
    background: var(--white);
}

.moment-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    font-size: 2rem;
    color: var(--white);
    transition: var(--transition);
}

.moment-card:hover .moment-icon {
    transform: scale(1.1) rotate(10deg);
}

.moment-card h3 {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--dark);
}

.moment-card p {
    color: var(--gray);
    font-size: 0.95rem;
    line-height: 1.7;
}

.moment-footer {
    margin-top: 25px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    color: var(--primary);
    font-weight: 600;
}

/* 轮播图容器 */
.carousel-container {
    position: relative;
    width: 100%;
    max-width: 300px;
    margin: 20px auto;
    overflow: hidden;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

/* 轮播图包装器 */
.carousel-wrapper {
    display: flex;
    transition: transform 0.5s ease-in-out;
}

/* 轮播图滑块 */
.carousel-slide {
    flex: 0 0 100%;
    width: 100%;
}

.carousel-slide img {
    display: block;
    width: 100%;
    height: 200px;
    object-fit: cover;
}

/* 轮播图按钮 */
.carousel-prev,
.carousel-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    color: var(--primary);
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    z-index: 10;
}

.carousel-prev:hover,
.carousel-next:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-50%) scale(1.1);
}

.carousel-prev {
    left: 10px;
}

.carousel-next {
    right: 10px;
}

/* 轮播图指示器 */
.carousel-indicators {
    position: absolute;
    bottom: 15px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 10;
}

.indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.6);
    cursor: pointer;
    transition: var(--transition);
}

.indicator:hover {
    background: rgba(255, 255, 255, 0.8);
}

.indicator.active {
    background: var(--primary);
    transform: scale(1.2);
}

.moment-footer i {
    animation: heartbeat 1.5s ease-in-out infinite;
}

/* ===== 情书区域 ===== */
.letter-section {
    padding: 100px 0;
    position: relative;
    z-index: 1;
}

.letter-container {
    display: flex;
    justify-content: center;
    gap: 50px;
    flex-wrap: wrap;
}

.letter-display {
    width: 500px;
    flex-shrink: 0;
}

.letter-paper {
    background: var(--white);
    padding: 50px 40px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    position: relative;
}

.letter-paper::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: var(--gradient);
    border-radius: 20px 20px 0 0;
}

.letter-title {
    font-family: 'Great Vibes', cursive;
    font-size: 2.2rem;
    color: var(--primary);
    margin-bottom: 10px;
    text-align: center;
}

.letter-date {
    text-align: center;
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px dashed var(--primary);
}

.letter-body p {
    color: var(--dark);
    line-height: 2.2;
    margin-bottom: 24px;
    font-family: 'Noto Serif SC', 'ZCOOL XiaoWei', serif;
    font-size: 1.05rem;
    text-align: justify;
    text-indent: 2em;
    letter-spacing: 1px;
    opacity: 0.92;
}

.letter-body p:first-child {
    text-indent: 0;
    text-align: center;
    font-family: 'ZCOOL XiaoWei', 'Ma Shan Zheng', cursive;
    font-size: 1.3rem;
    color: var(--primary);
    letter-spacing: 3px;
    margin-bottom: 30px;
}

.letter-body p:last-child {
    margin-bottom: 0;
    text-align: right;
    text-indent: 0;
    padding-right: 20px;
}

.letter-body p:last-child::before {
    content: '';
    display: inline-block;
    width: 40px;
    height: 1px;
    background: var(--primary);
    vertical-align: middle;
    margin-right: 15px;
    opacity: 0.5;
}

.letter-write h3 {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.6rem;
    margin-bottom: 15px;
    color: var(--dark);
}

.letter-write>p {
    color: var(--gray);
    margin-bottom: 30px;
}

.letter-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.letter-form input,
.letter-form textarea {
    width: 100%;
    padding: 18px 25px;
    border: 2px solid rgba(255, 107, 157, 0.2);
    border-radius: 15px;
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 1rem;
    background: var(--white);
    transition: var(--transition);
}

.letter-form input:focus,
.letter-form textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(255, 107, 157, 0.1);
}

.letter-form textarea {
    resize: vertical;
    min-height: 150px;
}

.letter-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 18px 40px;
    background: var(--gradient);
    color: var(--white);
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 5px 20px rgba(255, 107, 157, 0.3);
}

.letter-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(255, 107, 157, 0.4);
}

/* ===== 页脚 ===== */
.footer {
    background: linear-gradient(180deg, #2d3436 0%, #1a1a2e 100%);
    padding: 60px 0 30px;
    position: relative;
    z-index: 1;
}

.footer-content {
    text-align: center;
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary);
    font-family: 'Ma Shan Zheng', cursive;
    letter-spacing: 2px;
    margin-bottom: 15px;
}

.footer-logo i {
    animation: heartbeat 1.5s ease-in-out infinite;
}

.footer-text {
    color: rgba(255, 255, 255, 0.7);
    font-size: 1rem;
    margin-bottom: 25px;
}

.footer-divider {
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary), transparent);
    margin: 0 auto 25px;
    border-radius: 2px;
}

.footer-copy {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.85rem;
}

.footer-copy span {
    color: var(--primary);
    font-weight: 600;
}

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 55px;
    height: 55px;
    background: var(--gradient);
    border: none;
    border-radius: 50%;
    color: var(--white);
    font-size: 1.3rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
    box-shadow: 0 5px 20px rgba(255, 107, 157, 0.4);
}

.back-to-top.active {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(255, 107, 157, 0.5);
}

/* ===== 动画 ===== */
@keyframes float {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-10px);
    }
}

@keyframes heartbeat {

    0%,
    100% {
        transform: scale(1);
    }

    14% {
        transform: scale(1.1);
    }

    28% {
        transform: scale(1);
    }

    42% {
        transform: scale(1.15);
    }

    70% {
        transform: scale(1);
    }
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
    .envelope {
        width: 520px;
        height: 360px;
    }

    .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .gallery-item.wide {
        grid-column: span 2;
    }

    .moments-grid {
        gap: 30px;

        .letter-display {
            width: 450px;
        }
    }

    @media (max-width: 768px) {

        /* 导航菜单 */
        .nav-menu {
            position: fixed;
            top: 0;
            right: -100%;
            width: 80%;
            max-width: 300px;
            height: 100vh;
            background: var(--white);
            flex-direction: column;
            justify-content: center;
            align-items: center;
            gap: 30px;
            box-shadow: -10px 0 40px rgba(0, 0, 0, 0.1);
            transition: var(--transition);
            padding: 20px;
        }

        .nav-menu.active {
            right: 0;
        }

        .nav-toggle {
            display: flex;
            z-index: 1001;
        }

        .nav-link {
            font-size: 1.2rem;
            padding: 15px 25px;
            border-radius: 30px;
            transition: all 0.3s ease;
        }

        .nav-link:hover,
        .nav-link.active {
            background: rgba(255, 107, 157, 0.1);
        }

        /* 信封 */
        .envelope {
            width: 90%;
            max-width: 420px;
            height: auto;
            aspect-ratio: 580 / 400;
        }

        .envelope-section {
            padding: 80px 15px;
            min-height: calc(100vh - 70px);
        }

        .seal-ring {
            width: 65px;
            height: 65px;
        }

        .seal-icon {
            font-size: 2rem;
        }

        /* 信封装饰简化 */
        .envelope-flap .flap-corner.bl,
        .envelope-flap .flap-corner.br {
            display: none;
        }

        .envelope-flap .flap-stripes {
            gap: 10px;
        }

        .envelope-flap .flap-stripes .stripe {
            height: 2px;
        }

        .envelope-ribbon .ribbon-main {
            height: 13px;
            left: 3.5%;
            right: 3.5%;
        }

        .envelope-ribbon .ribbon-bow {
            width: 42px;
            height: 36px;
        }

        .envelope-ribbon .bow-left,
        .envelope-ribbon .bow-right {
            width: 15px;
            height: 15px;
        }

        .envelope-ribbon .bow-center {
            width: 9px;
            height: 9px;
        }

        /* 轮播图 */
        .carousel-container {
            max-width: 300px;
            margin: 20px auto;
        }

        .carousel-slide img {
            height: 220px;
        }

        .carousel-prev,
        .carousel-next {
            width: 38px;
            height: 38px;
            font-size: 1.4rem;
        }

        .letter-to {
            font-size: 1.2rem;
        }

        .letter-body p {
            font-size: 1rem;
            line-height: 2;
        }

        /* 时间线 */
        .timeline-line {
            left: 20px;
        }

        .timeline-item.left,
        .timeline-item.right {
            padding-left: 60px;
            padding-right: 15px;
            text-align: left;
            margin-bottom: 50px;
        }

        .timeline-item.left .timeline-icon,
        .timeline-item.right .timeline-icon {
            left: -15px;
            right: auto;
            width: 45px;
            height: 45px;
            font-size: 1.1rem;
        }

        .timeline-item.left .timeline-content,
        .timeline-item.right .timeline-content {
            margin-left: 0;
            margin-right: 0;
            padding: 25px 20px;
        }

        .timeline-content h3 {
            font-size: 1.3rem;
        }

        .timeline-content p {
            font-size: 0.9rem;
        }

        .timeline-image img {
            height: 150px;
        }

        /* 相册 */
        .gallery-grid {
            grid-template-columns: 1fr;
            gap: 15px;
        }

        .gallery-item.wide,
        .gallery-item.tall {
            grid-column: span 1;
            grid-row: span 1;
            aspect-ratio: 1;
        }

        /* 时光卡片 */
        .moments-grid {
            flex-direction: column;
            align-items: center;
            gap: 25px;
        }

        .moment-card {
            width: 100%;
            max-width: 340px;
            padding: 35px 25px;
        }

        /* 情书 */
        .letter-container {
            flex-direction: column;
            align-items: center;
            gap: 30px;
        }

        .letter-display {
            width: 100%;
            max-width: 450px;
        }

        .letter-paper {
            padding: 40px 25px;
        }

        .letter-title {
            font-size: 1.8rem;
        }

        .letter-body p {
            font-size: 0.95rem;
            line-height: 1.9;
        }

        /* 通用 */
        .section-title {
            font-size: 2rem;
        }

        .section-desc {
            font-size: 1rem;
            padding: 0 15px;
        }

        .back-to-top {
            right: 20px;
            bottom: 20px;
            width: 50px;
            height: 50px;
            font-size: 1.1rem;
        }

        .footer-text {
            font-size: 0.9rem;
            padding: 0 15px;
        }
    }

    @media (max-width: 480px) {

        /* 信封 */
        .envelope {
            width: 95%;
            max-width: 340px;
            aspect-ratio: 580 / 400;
        }

        .seal-ring {
            width: 55px;
            height: 55px;
        }

        .seal-icon {
            font-size: 1.6rem;
        }

        .paper-content {
            padding: 20px 15px;
        }

        .letter-header {
            margin-bottom: 18px;
            padding-bottom: 12px;
        }

        .letter-date {
            font-size: 0.75rem;
            margin-bottom: 6px;
        }

        .letter-to {
            font-size: 1.1rem;
            letter-spacing: 2px;
        }

        .letter-body {
            gap: 12px;
        }

        .letter-body p {
            font-size: 0.95rem;
            line-height: 2;
            margin-bottom: 0;
            letter-spacing: 1px;
        }

        .letter-body p:first-child {
            font-size: 1.3rem;
            margin-bottom: 5px;
        }

        .letter-footer {
            padding-top: 15px;
        }

        .letter-footer p {
            font-size: 0.9rem;
            line-height: 1.8;
            margin-bottom: 10px;
        }

        .letter-signature {
            font-size: 1.3rem !important;
        }

        .envelope-hint p {
            font-size: 1rem;
            letter-spacing: 2px;
        }

        /* 信封装饰简化 */
        .envelope-flap .flap-frame {
            display: none;
        }

        .envelope-flap .flap-corner.tl,
        .envelope-flap .flap-corner.tr {
            display: none;
        }

        .envelope-flap .flap-stripes {
            gap: 8px;
        }

        .envelope-flap .flap-stripes .stripe {
            height: 2px;
        }

        .envelope-ribbon .ribbon-main {
            height: 12px;
            left: 4%;
            right: 4%;
        }

        .envelope-ribbon .ribbon-bow {
            width: 40px;
            height: 35px;
        }

        .envelope-ribbon .bow-left,
        .envelope-ribbon .bow-right {
            width: 14px;
            height: 14px;
        }

        .envelope-ribbon .bow-center {
            width: 9px;
            height: 9px;
        }

        .envelope-left .heart-trails,
        .envelope-right .heart-trails {
            display: none;
        }

        /* 轮播图优化 */
        .carousel-container {
            max-width: 280px;
            margin: 15px auto;
        }

        .carousel-slide img {
            height: 200px;
        }

        .carousel-prev,
        .carousel-next {
            width: 36px;
            height: 36px;
            font-size: 1.3rem;
        }

        /* 信封控制按钮 */
        .envelope-controls {
            gap: 10px;
        }

        .control-btn {
            width: 44px;
            height: 44px;
            font-size: 1.1rem;
        }

        /* 时间线 */
        .timeline-line {
            left: 15px;
        }

        .timeline-item.left,
        .timeline-item.right {
            padding-left: 50px;
            padding-right: 10px;
            margin-bottom: 40px;
        }

        .timeline-item.left .timeline-icon,
        .timeline-item.right .timeline-icon {
            left: -12px;
            width: 40px;
            height: 40px;
            font-size: 1rem;
        }

        .timeline-content {
            padding: 20px 15px;
        }

        .timeline-content h3 {
            font-size: 1.15rem;
        }

        .timeline-content p {
            font-size: 0.85rem;
            line-height: 1.7;
        }

        .timeline-image img {
            height: 120px;
        }

        /* 相册 */
        .gallery-grid {
            gap: 12px;
        }

        .gallery-item {
            border-radius: 15px;
        }

        /* 时光卡片 */
        .moment-card {
            padding: 30px 20px;
        }

        .moment-icon {
            width: 70px;
            height: 70px;
            font-size: 1.7rem;
            margin-bottom: 20px;
        }

        .moment-card h3 {
            font-size: 1.15rem;
        }

        .moment-card p {
            font-size: 0.85rem;
        }

        /* 情书 */
        .letter-paper {
            padding: 30px 20px;
        }

        .letter-title {
            font-size: 1.5rem;
        }

        .letter-date {
            font-size: 0.8rem;
            margin-bottom: 20px;
        }

        .letter-body p {
            font-size: 0.85rem;
            line-height: 1.8;
            margin-bottom: 15px;
        }

        /* 通用 */
        .container {
            padding: 0 15px;
        }

        .section-header {
            margin-bottom: 50px;
        }

        .section-title {
            font-size: 1.6rem;
        }

        .section-tag {
            font-size: 0.8rem;
            letter-spacing: 2px;
        }

        .section-desc {
            font-size: 0.9rem;
            padding: 0 10px;
        }

        .carousel-container {
            max-width: 280px;
            margin: 0 auto;
        }

        /* 轮播图优化 */
        .carousel-container {
            max-width: 260px;
        }

        .carousel-slide img {
            height: 180px;
        }

        .carousel-prev,
        .carousel-next {
            width: 32px;
            height: 32px;
            font-size: 1.2rem;
        }

        .carousel-indicators {
            bottom: 10px;
        }

        .indicator {
            width: 8px;
            height: 8px;
        }

        /* 信封装饰优化 */
        .envelope-ribbon .ribbon-main {
            height: 10px;
            left: 5%;
            right: 5%;
        }

        .envelope-ribbon .ribbon-bow {
            width: 35px;
            height: 30px;
        }

        .envelope-ribbon .bow-left,
        .envelope-ribbon .bow-right {
            width: 12px;
            height: 12px;
        }

        .envelope-ribbon .bow-center {
            width: 8px;
            height: 8px;
        }

        .envelope-flap .flap-frame {
            display: none;
        }

        .envelope-flap .flap-corner {
            display: none;
        }

        .envelope-flap .center-heart {
            font-size: 20px;
        }

        .envelope-flap .pulse-ring {
            display: none;
        }

        .envelope-flap .flap-stripes {
            display: none;
        }

        .envelope-left .floating-heart,
        .envelope-right .floating-heart {
            font-size: 12px;
        }

        .envelope-left .star-1,
        .envelope-left .star-2,
        .envelope-right .star-3,
        .envelope-right .star-4 {
            display: none;
        }

        .envelope-left .heart-trails,
        .envelope-right .heart-trails {
            display: none;
        }

        /* 信封控制按钮优化 */
        .envelope-controls {
            gap: 8px;
        }

        .control-btn {
            width: 40px;
            height: 40px;
            font-size: 1rem;
        }

        /* 音乐控制按钮优化 */
        .music-control {
            width: 42px;
            height: 42px;
            font-size: 1rem;
        }

        .story,
        .gallery,
        .moments,
        .letter {
            padding: 60px 0;
        }

        .scroll-indicator {
            bottom: 30px;
        }

        .back-to-top {
            right: 15px;
            bottom: 15px;
            width: 45px;
            height: 45px;
            font-size: 1rem;
        }

        .footer {
            padding: 40px 0 20px;
        }

        .footer-logo {
            font-size: 1.3rem;
        }

        .footer-text {
            font-size: 0.85rem;
        }

        .footer-copy {
            font-size: 0.75rem;
        }
    }

    @media (max-width: 320px) {

        /* 超小屏幕优化 */
        .envelope {
            width: 98%;
            max-width: 280px;
        }

        .seal-ring {
            width: 48px;
            height: 48px;
        }

        .seal-icon {
            font-size: 1.4rem;
        }

        .letter-body p {
            font-size: 0.75rem;
        }

        .letter-body p:first-child {
            font-size: 1rem;
        }

        .nav-menu {
            width: 90%;
        }

        .nav-link {
            font-size: 1.1rem;
        }
    }