:root {
    --bg-color: #F8F7F5;
    --primary-color: #3D4A52;
    --secondary-color: #8A9499;
    --accent-color: #B89B72;
    --text-dark: #2C2E30;
    --text-light: #F8F7F5;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-dark);
    overflow-x: hidden;
    scroll-behavior: smooth;
}

/* 背景流体渐变效果 */
body::before {
    content: '';
    position: fixed;
    inset: -40%;
    background:
        radial-gradient(circle at 10% 20%, rgba(184, 155, 114, 0.45), transparent 55%),
        radial-gradient(circle at 80% 0%, rgba(61, 74, 82, 0.55), transparent 60%),
        radial-gradient(circle at 50% 80%, rgba(138, 148, 153, 0.55), transparent 55%);
    mix-blend-mode: multiply;
    opacity: 0.45;
    filter: blur(40px);
    z-index: -1;
    pointer-events: none;
    animation: fluidMove 24s ease-in-out infinite alternate;
}

@keyframes fluidMove {
    0% {
        transform: translate3d(0, 0, 0) scale(1);
    }
    50% {
        transform: translate3d(-4%, 3%, 0) scale(1.05);
    }
    100% {
        transform: translate3d(4%, -3%, 0) scale(1.08);
    }
}

.font-serif-cn {
    font-family: 'Noto Serif SC', serif;
}

.font-sans-cn {
    font-family: 'Noto Sans SC', sans-serif;
}

.slide {
    position: relative;
    width: 100%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 4rem 2rem;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.9s cubic-bezier(0.22, 0.61, 0.36, 1),
                transform 0.9s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.slide.visible {
    opacity: 1;
    transform: translateY(0);
}


.navigation {
    position: fixed;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.nav-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: rgba(61, 74, 82, 0.3);
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    position: relative;
}

.nav-dot:hover {
    background-color: var(--accent-color);
    transform: scale(1.2);
}

.nav-dot.active {
    background-color: var(--accent-color);
    border-color: var(--primary-color);
    transform: scale(1.3);
}

/* 导航点悬停提示 */
.nav-dot::after {
    content: attr(data-title);
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(61, 74, 82, 0.95);
    color: white;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.75rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
    transform: translateY(-50%) translateX(-10px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    z-index: 1001;
}

.nav-dot::before {
    content: '';
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
    border-left: 6px solid rgba(61, 74, 82, 0.95);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
    transform: translateY(-50%) translateX(-10px);
    z-index: 1002;
}

.nav-dot:hover::after,
.nav-dot:hover::before {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.source-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 0.75rem;
    transition: color 0.3s ease;
}

.source-link:hover {
    color: var(--accent-color);
}

.source-text {
    color: var(--secondary-color);
    font-size: 0.75rem;
    line-height: 1.6;
}

.chart-container {
    width: 100%;
    height: 400px;
    margin: 1rem 0;
    position: relative;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.chart-container.loaded {
    opacity: 1;
    transform: translateY(0);
}

.chart-container::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 40px;
    height: 40px;
    border: 3px solid var(--accent-color);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.chart-container:not(.loaded)::before {
    opacity: 1;
}

@keyframes spin {
    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

.data-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-bg {
    background-image: url('./cover_background.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.chapter-bg-1 {
    background-image: url('./chapter1_aging.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.chapter-bg-2 {
    background-image: url('./chapter2_marriage.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.chapter-bg-3 {
    background-image: url('./chapter3_parenting.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.chapter-bg-4 {
    background-image: url('./chapter4_policy.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.gradient-overlay {
    background: linear-gradient(135deg, rgba(61, 74, 82, 0.85) 0%, rgba(138, 148, 153, 0.75) 100%);
}

.number-highlight {
    color: var(--accent-color);
    font-weight: 700;
    font-size: 1.2em;
}

/* 音乐播放按钮样式 */
.music-toggle {
    position: fixed;
    top: 2rem;
    right: 5rem;
    z-index: 1001;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border: 2px solid rgba(184, 155, 114, 0.3);
    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 4px 20px rgba(0, 0, 0, 0.1);
}

.music-toggle:hover {
    transform: scale(1.1);
    background: rgba(255, 255, 255, 1);
    border-color: var(--accent-color);
    box-shadow: 0 6px 24px rgba(184, 155, 114, 0.3);
}

.music-toggle.playing {
    background: rgba(184, 155, 114, 0.15);
    border-color: var(--accent-color);
    animation: musicPulse 2s ease-in-out infinite;
}

@keyframes musicPulse {
    0%, 100% {
        box-shadow: 0 4px 20px rgba(184, 155, 114, 0.2);
    }
    50% {
        box-shadow: 0 4px 30px rgba(184, 155, 114, 0.4);
    }
}

.music-icon {
    width: 28px;
    height: 28px;
    fill: var(--primary-color);
    transition: fill 0.3s ease;
}

.music-toggle:hover .music-icon,
.music-toggle.playing .music-icon {
    fill: var(--accent-color);
}

.music-toggle .pause-icon {
    display: none;
}

.music-toggle.playing .play-icon {
    display: none;
}

.music-toggle.playing .pause-icon {
    display: block;
}

/* 阅读进度条 */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: rgba(0, 0, 0, 0.05);
    z-index: 10000;
    pointer-events: none;
}

.reading-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color), var(--primary-color));
    width: 0%;
    transition: width 0.1s ease-out;
    box-shadow: 0 0 10px rgba(184, 155, 114, 0.5);
}

/* 滚动百分比显示 */
.scroll-percentage {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    padding: 0.5rem 1rem;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(184, 155, 114, 0.3);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary-color);
    transition: all 0.3s ease;
    opacity: 0.7;
}

.scroll-percentage:hover {
    opacity: 1;
    transform: scale(1.05);
}

/* 数据卡片3D效果增强 */
.data-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transform-style: preserve-3d;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.3s ease;
    position: relative;
    overflow: hidden;
}

.data-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s ease;
}

.data-card:hover::before {
    left: 100%;
}

.data-card:hover {
    transform: translateY(-8px) rotateX(2deg) rotateY(-2deg);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.2);
    border-color: var(--accent-color);
}

.data-card:active {
    transform: translateY(-4px) rotateX(1deg) rotateY(-1deg);
    transition: transform 0.1s ease;
}

/* 打字机效果 */
.typewriter-text {
    overflow: hidden;
    white-space: nowrap;
    position: relative;
}

.typewriter-text::after {
    content: '|';
    color: var(--accent-color);
    font-weight: bold;
    animation: blink-caret 0.75s step-end infinite;
    margin-left: 2px;
}

.typewriter-text.completed::after {
    display: none;
}

@keyframes blink-caret {
    from, to {
        opacity: 1;
    }
    50% {
        opacity: 0;
    }
}

/* 数字滚动动画 */
.number-counter {
    display: inline-block;
}

@media (max-width: 768px) {
    .navigation {
        right: 1rem;
    }
    
    .slide {
        padding: 3rem 1rem;
    }
    
    .chart-container {
        height: 300px;
    }
    
    .music-toggle {
        top: 1rem;
        right: 4rem;
        width: 48px;
        height: 48px;
    }
    
    .music-icon {
        width: 24px;
        height: 24px;
    }
    
    .data-card:hover {
        transform: translateY(-4px);
    }
    
    .scroll-percentage {
        bottom: 1rem;
        right: 1rem;
        font-size: 0.75rem;
        padding: 0.4rem 0.8rem;
    }
    
    .nav-dot::after {
        font-size: 0.7rem;
        padding: 4px 8px;
    }
}