:root {
    --bg: #1a1d23;
    --surface: #252830;
    --primary: #f6853b;
    --primary-glow: rgba(246, 133, 59, 0.3);
    --text: #e8e8e8;
    --text-secondary: #a0a3ab;
    --card-bg: #2a2d35;
    --border: #3a3d45;
    --shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    background: #0f1117;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    color: var(--text);
}

.presentation-container {
    width: 100%;
    max-width: 1100px;
    aspect-ratio: 16 / 9;
    background: var(--bg);
    border-radius: 20px;
    overflow: hidden;
    position: relative;
    box-shadow: var(--shadow), 0 0 0 1px var(--border);
    display: flex;
    flex-direction: column;
    margin: 0 auto 16px auto;
}

.slides-wrapper {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 36px 48px;
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.45s cubic-bezier(0.2, 0.9, 0.4, 1.1), transform 0.45s ease;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: radial-gradient(circle at 20% 30%, #1e2230 0%, var(--bg) 70%);
    overflow-y: auto;
}

.slide.active {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
    z-index: 10;
}

.slide.exiting {
    opacity: 0;
    transform: translateX(-30px);
}

.slide::-webkit-scrollbar {
    width: 4px;
}
.slide::-webkit-scrollbar-track {
    background: #252830;
    border-radius: 4px;
}
.slide::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: 4px;
}

.slide-title {
    font-size: clamp(1.2rem, 3vw, 2rem);
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.3;
    color: white;
}

.slide-title .highlight {
    color: var(--primary);
    text-shadow: 0 0 20px var(--primary-glow);
}

.slide-subtitle {
    font-size: clamp(0.8rem, 1.8vw, 1.1rem);
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    max-width: 85%;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 18px;
    width: 100%;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 16px;
    transition: all 0.3s ease;
}

.card:hover {
    border-color: var(--primary);
    box-shadow: 0 0 15px var(--primary-glow);
    transform: translateY(-3px);
}

.card h3 {
    font-size: clamp(0.9rem, 2vw, 1.1rem);
    margin-bottom: 0.5rem;
    color: white;
}

.card p {
    color: var(--text-secondary);
    font-size: clamp(0.7rem, 1.5vw, 0.9rem);
    line-height: 1.5;
}

.data-highlight {
    font-size: clamp(1.2rem, 3vw, 1.9rem);
    font-weight: 800;
    color: var(--primary);
    display: inline-block;
}

.badge {
    background: rgba(246, 133, 59, 0.15);
    color: var(--primary);
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 0.4rem;
}

.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    width: 100%;
}

.arch-layer {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    justify-content: center;
}

.layer-node {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 12px 14px;
    min-width: 90px;
    text-align: center;
    font-weight: 600;
    color: white;
    font-size: clamp(0.7rem, 1.5vw, 0.9rem);
}

.layer-node.primary-node {
    border-color: var(--primary);
    box-shadow: 0 0 12px var(--primary-glow);
    background: rgba(246, 133, 59, 0.1);
}

.arrow-connector {
    font-size: 1.4rem;
    color: var(--primary);
}

.cta-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 14px 28px;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-block;
    text-decoration: none;
    box-shadow: 0 4px 20px var(--primary-glow);
}

.cta-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 25px rgba(246, 133, 59, 0.5);
}

.page-indicator {
    position: absolute;
    bottom: 16px;
    right: 24px;
    color: var(--text-secondary);
    font-size: 0.8rem;
    background: rgba(0, 0, 0, 0.4);
    padding: 4px 12px;
    border-radius: 20px;
}

.nav-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 24px;
    background: var(--surface);
    border-top: 1px solid var(--border);
}

.center-nav {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.auto-timer {
    font-size: 0.75rem;
    font-weight: 600;
    background: rgba(246, 133, 59, 0.2);
    padding: 2px 10px;
    border-radius: 20px;
    color: var(--primary);
    letter-spacing: 0.5px;
    min-width: 100px;
    text-align: center;
}

.nav-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
    font-size: 0.9rem;
}

.nav-btn:hover {
    background: var(--primary);
    border-color: var(--primary);
}

.nav-btn:disabled {
    opacity: 0.4;
    pointer-events: none;
}

.dot-navigation {
    display: flex;
    gap: 6px;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--border);
    transition: all 0.3s;
    cursor: pointer;
}

.dot.active {
    background: var(--primary);
    box-shadow: 0 0 8px var(--primary-glow);
    width: 24px;
    border-radius: 10px;
}

table.clean-table {
    width: 100%;
    border-collapse: collapse;
    color: var(--text);
    font-size: clamp(0.7rem, 1.5vw, 0.9rem);
}

table.clean-table th {
    text-align: left;
    padding: 8px 4px;
    border-bottom: 1px solid var(--border);
    color: var(--primary);
}

table.clean-table td {
    padding: 8px 4px;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}

.transition-intro {
    color: var(--text-secondary);
    font-style: italic;
    font-size: clamp(0.8rem, 1.5vw, 0.95rem);
    margin-bottom: 1.5rem;
    line-height: 1.6;
    border-left: 2px solid var(--primary);
    padding-left: 16px;
}

.footer-beian {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(4px);
    border-radius: 40px;
    padding: 8px 20px;
    margin-top: 8px;
    font-size: 12px;
}
.footer-beian a {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    color: #ccc;
    transition: color 0.2s;
}
.footer-beian a:hover {
    color: var(--primary);
}
.footer-beian img {
    width: 18px;
    height: 18px;
}
.footer-beian p {
    margin: 0;
    line-height: 20px;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    .presentation-container {
        aspect-ratio: auto;
        min-height: 70vh;
        border-radius: 12px;
    }
    .slide {
        padding: 20px 24px;
    }
    .two-col {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .content-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    .arch-layer {
        flex-direction: column;
        gap: 8px;
    }
    .layer-node {
        min-width: auto;
        width: 100%;
    }
    .arrow-connector {
        display: none;
    }
    .nav-btn {
        padding: 8px 16px;
        font-size: 0.8rem;
    }
    .cta-btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    .footer-beian {
        gap: 12px;
        padding: 6px 12px;
    }
    .auto-timer {
        font-size: 0.7rem;
        min-width: 80px;
    }
}
/* ========== 新增：第一页封面居中 ========== */
.slide:first-child {
    text-align: center;
    justify-content: center;  /* 垂直居中 */
}

.slide:first-child .slide-title,
.slide:first-child .slide-subtitle {
    text-align: center;
    max-width: 100%;         /* 移除原85%限制，使文本完整居中 */
    margin-left: auto;
    margin-right: auto;
}

/* 封面内的其他内容（🦞和描述）自然继承 text-align: center */