:root {
    --bg-body: #f8fafc;
    --bg-card: #ffffff;
    --bg-card-alt: #f9f7f3;
    --bg-em: #fefcf7;
    --gold: #b8862d;
    --gold-light: #c8963e;
    --gold-pale: #9a6d1f;
    --gold-bg: rgba(184, 134, 45, 0.06);
    --gold-border: rgba(184, 134, 45, 0.4);
    --text-primary: #2c2c2c;
    --text-secondary: #3d3d3d;
    --text-body: #5a5a5a;
    --text-muted: #7a7a7a;
    --text-light: #999999;
    --border-light: #e5e0d8;
    --border-card: #eae6de;
    --accent-blue: #3b6fb6;
    --accent-teal: #2a8c7e;
    --red-tag: #c0392b;
    --shadow-card: 0 2px 16px rgba(0, 0, 0, 0.06), 0 0 1px rgba(0, 0, 0, 0.04);
    --shadow-card-hover: 0 8px 28px rgba(0, 0, 0, 0.1), 0 0 1px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 18px 50px rgba(0, 0, 0, 0.1), 0 0 1px rgba(0, 0, 0, 0.04);
    --shadow-cta: 0 8px 36px rgba(184, 134, 45, 0.22), 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-cta-hover: 0 14px 44px rgba(184, 134, 45, 0.32), 0 6px 20px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --font-serif: 'Microsoft YaHei', 'STSong', 'Songti SC', 'SimSun', 'KaiTi', '楷体', 'STKaiti', serif;
    --font-sans: -apple-system, 'Microsoft YaHei', 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', sans-serif;
    --transition-smooth: 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--text-body);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    background-image: radial-gradient(ellipse at 50% 0%, rgba(184, 134, 45, 0.03) 0%, transparent 65%),
    radial-gradient(ellipse at 85% 20%, rgba(59, 111, 182, 0.02) 0%, transparent 55%),
    radial-gradient(ellipse at 15% 60%, rgba(42, 140, 126, 0.02) 0%, transparent 50%);
    background-attachment: fixed;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    opacity: 0.018;
    background-image: linear-gradient(rgba(0, 0, 0, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 0, 0, 0.06) 1px, transparent 1px);
    background-size: 40px 40px;
}

.container {
    position: relative;
    z-index: 1;
    max-width: 720px;
    margin: 0 auto;
}

.hero {
    text-align: center;
    padding: 50px 16px 36px;
    position: relative;
}

.hero-badge {
    display: inline-block;
    background: var(--gold-bg);
    border: 1px solid var(--gold-border);
    color: var(--gold-pale);
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    padding: 8px 18px;
    border-radius: 50px;
    margin-bottom: 20px;
    text-transform: uppercase;
}

.hero h1 {
    font-family: var(--font-serif);
    font-size: clamp(2.6rem, 4.5vw, 4rem);
    font-weight: 700;
    letter-spacing: 0.03em;
    line-height: 1.25;
    background: linear-gradient(180deg, #c8963e 0%, #9a6d1f 40%, #7a4f0a 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 8px;
}

.hero .subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    letter-spacing: 0.04em;
    font-weight: 400;
}

.hero-divider {
    width: 50px;
    height: 2px;
    background: var(--gold);
    margin: 16px auto 0;
    border-radius: 1px;
    opacity: 0.8;
}

.section {
    margin-bottom: 36px;
}

.section-label {
    display: inline-block;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    color: var(--gold-pale);
    text-transform: uppercase;
    margin-bottom: 6px;
    padding: 4px 12px;
    border: 1px solid var(--gold-border);
    border-radius: 50px;
    background: var(--gold-bg);
}

.section h2 {
    font-family: var(--font-serif);
    /* 原先: clamp(2.08rem, 3.5vw, 2.8rem) → 向上取整至一位小数 2.1rem */
    font-size: clamp(2.1rem, 3.5vw, 2.8rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 6px;
    letter-spacing: 0.02em;
    line-height: 1.35;
}

.section h3 {
    font-family: var(--font-serif);
    font-size: 1.7rem;
    font-weight: 700;
    color: #2a2a2a;
    margin: 16px 0 6px;
    letter-spacing: 0.02em;
}

.section .intro-text {
    font-size: 1.4rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin-bottom: 12px;
}

.section p {
    font-size: 1.4rem;
    color: var(--text-body);
    line-height: 1.8;
    margin-bottom: 10px;
}

.section .highlight {
    color: var(--gold-pale);
    font-weight: 600;
}

.section .em-block {
    background: var(--bg-em);
    border-left: 3px solid var(--gold);
    padding: 14px 16px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 14px 0;
    font-size: 1.4rem;
    color: var(--text-secondary);
    line-height: 1.7;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.03);
}

.section .em-block strong {
    color: var(--gold-pale);
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: var(--radius-lg);
    padding: 22px 18px;
    margin-bottom: 14px;
    box-shadow: var(--shadow-card);
    transition: border-color var(--transition-smooth), box-shadow var(--transition-smooth);
}

.card:hover {
    border-color: var(--gold-border);
    box-shadow: var(--shadow-card-hover);
}

.card h4 {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
    letter-spacing: 0.02em;
}

.card .card-icon {
    font-size: 2.4rem;
    margin-right: 6px;
    vertical-align: -3px;
}

.card p {
    font-size: 1.5rem;
    color: #5a5a5a;
    line-height: 1.65;
    margin: 0;
}

.vip-features-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 20px;
}

.vip-feature-item {
    background: var(--bg-card-alt);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 16px 14px;
    text-align: center;
    transition: all var(--transition-smooth);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.vip-feature-item:hover {
    border-color: var(--gold-border);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(184, 134, 45, 0.1);
    background: #fefdfa;
}

.vip-feature-item .feat-icon {
    font-size: 3.2rem;
    display: block;
    margin-bottom: 6px;
}

.vip-feature-item .feat-title {
    font-weight: 700;
    font-size: 1.7rem;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.vip-feature-item .feat-desc {
    font-size: 1.4rem;
    color: #2c2c2c;
    line-height: 1.5;
}

.carousel-wrapper {
    position: relative;
    overflow: hidden;
    width: 100%;
}

.carousel-wrapper:active {
    cursor: grabbing;
}

.carousel-track {
    display: flex;
    flex-wrap: nowrap;
    transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    will-change: transform;
}

.carousel-slide {
    flex: 0 0 100%;
    width: 100%;
    position: relative;
}

.carousel-slide img {
    width: 100%;
    display: block;
}

.carousel-track, .carousel-slide {
    margin: 0;
    padding: 0;
}

.slide-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px 16px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
    color: #fff;
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    pointer-events: none;
}

.carousel-dots {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 10px;
}

.carousel-dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: #d5d0c8;
    border: none;
    cursor: pointer;
    transition: all var(--transition-smooth);
    padding: 0;
}

.carousel-dot.active {
    background: var(--gold);
    box-shadow: 0 0 8px rgba(184, 134, 45, 0.35);
    width: 24px;
    border-radius: 10px;
}

.carousel-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 2;
    background: rgba(255, 255, 255, 0.85);
    border: 1px solid rgba(0, 0, 0, 0.12);
    color: #3d3d3d;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.6rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-smooth);
    backdrop-filter: blur(8px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.carousel-arrow:hover {
    background: rgba(255, 255, 255, 0.95);
    border-color: var(--gold);
    color: var(--gold-pale);
    box-shadow: 0 4px 14px rgba(184, 134, 45, 0.2);
}

.carousel-arrow.prev {
    left: 10px;
}

.carousel-arrow.next {
    right: 10px;
}

.cta-section {
    background: #fefdfa;
    border: 2px solid var(--gold-border);
    border-radius: var(--radius-xl);
    padding: 28px 20px 24px;
    text-align: center;
    margin: 32px 0 40px;
    position: relative;
    box-shadow: var(--shadow-cta), var(--shadow-lg);
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: -40px;
    right: -40px;
    width: 120px;
    height: 120px;
    background: radial-gradient(circle, rgba(184, 134, 45, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.cta-tag {
    display: inline-block;
    background: #c0392b;
    color: #fff;
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    padding: 5px 14px;
    border-radius: 50px;
    margin-bottom: 14px;
    animation: pulseTag 2s ease-in-out infinite;
}

@keyframes pulseTag {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(192, 57, 43, 0.35);
    }
    50% {
        box-shadow: 0 0 0 14px rgba(192, 57, 43, 0);
    }
}

.cta-section .original-price {
    font-size: 1.6rem;
    color: #999;
    text-decoration: line-through;
    margin-bottom: 2px;
    letter-spacing: 0.03em;
}

.cta-section .special-price {
    font-family: var(--font-serif);
    font-size: clamp(4.5rem, 8vw, 6rem);
    font-weight: 900;
    color: #2a1f0a;
    letter-spacing: 0.02em;
    line-height: 1;
    margin: 4px 0;
}

.cta-section .special-price .currency {
    font-size: 1.9rem;
    vertical-align: super;
    font-weight: 600;
    margin-right: 2px;
    color: var(--gold);
}

.cta-section .save-badge {
    display: inline-block;
    background: var(--gold-bg);
    color: var(--gold-pale);
    font-size: 1.4rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 50px;
    margin-bottom: 10px;
    letter-spacing: 0.04em;
    border: 1px solid rgba(184, 134, 45, 0.2);
}

.btn-cta {
    display: inline-block;
    background: linear-gradient(135deg, #d4a853 0%, #b8862d 40%, #9a6d1f 100%);
    color: #fff;
    font-weight: 800;
    font-size: 1.7rem;
    letter-spacing: 0.06em;
    padding: 16px 48px;
    border-radius: 50px;
    text-decoration: none;
    box-shadow: var(--shadow-cta);
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
    font-family: var(--font-sans);
}

.btn-cta:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-cta-hover);
    background: linear-gradient(135deg, #e0b860 0%, #c8963e 40%, #a87a28 100%);
    color: #fff;
}

.btn-cta:active {
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(184, 134, 45, 0.25);
    transition: 0.1s;
}

.btn-cta::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -60%;
    width: 50%;
    height: 200%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.25), transparent);
    transform: skewX(-25deg);
    transition: 0.6s;
}

.btn-cta:hover::after {
    left: 120%;
}

.cta-guarantee {
    font-size: 1.2rem;
    color: #999;
    margin-top: 10px;
    letter-spacing: 0.03em;
}

.countdown-row {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin: 12px 0;
    flex-wrap: wrap;
}

.countdown-item {
    background: #f5f2eb;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    padding: 8px 10px;
    min-width: 44px;
    text-align: center;
}

.countdown-item .cd-num {
    font-size: 2.2rem;
    font-weight: 800;
    color: #2a1f0a;
    line-height: 1;
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'Menlo', 'Consolas', 'Courier New', monospace;
}

.countdown-item .cd-label {
    font-size: 01.2rem;
    color: #8a857c;
    letter-spacing: 0.04em;
    margin-top: 2px;
}

.footer-note {
    text-align: center;
    font-size: 1.2rem;
    color: #b0ada6;
    padding: 20px 0 30px;
    letter-spacing: 0.03em;
}

.fade-in {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

@media (max-width: 480px) {
    .container {
        padding: 0 14px;
    }

    .hero {
        padding: 36px 8px 24px;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .vip-features-grid {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }

    .vip-feature-item {
        padding: 12px 10px;
    }

    .vip-feature-item .feat-icon {
        font-size: 2.5rem;
    }

    .vip-feature-item .feat-title {
        font-size: 1.4rem;
    }

    .vip-feature-item .feat-desc {
        font-size: 1.4rem;
    }

    .carousel-wrapper {
        aspect-ratio: 4 / 3;
        max-height: 280px;
        border-radius: var(--radius-md);
    }

    .carousel-arrow {
        width: 30px;
        height: 30px;
        font-size: 1.4rem;
    }

    .carousel-arrow.prev {
        left: 6px;
    }

    .carousel-arrow.next {
        right: 6px;
    }

    .slide-overlay {
        font-size: 1.2rem;
        padding: 12px 12px 8px;
    }

    .btn-cta {
        font-size: 1.5rem;
        padding: 14px 36px;
        width: 85%;
        max-width: 320px;
    }

    .cta-section {
        padding: 22px 14px 20px;
        border-radius: var(--radius-lg);
    }

    .cta-section .special-price {
        font-size: 3.8rem;
    }

    .countdown-item {
        min-width: 36px;
        padding: 6px 7px;
    }

    .countdown-item .cd-num {
        font-size: 1.7rem;
    }

    .card {
        padding: 16px 14px;
    }

    .section p {
        font-size: 1.4rem;
    }
}

@media (min-width: 481px) and (max-width: 768px) {
    .carousel-wrapper {
        aspect-ratio: 16 / 10;
        max-height: 340px;
    }

    .btn-cta {
        font-size: 1.6rem;
        padding: 15px 42px;
    }

    .slide-overlay {
        font-size: 1.2rem;
    }

    .carousel-arrow {
        width: 32px;
        height: 32px;
        font-size: 1.4rem;
    }
}

@media (min-width: 769px) {
    .carousel-wrapper {
        aspect-ratio: 16 / 9;
        max-height: 420px;
    }

    .vip-features-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 14px;
    }

    .section p {
        font-size: 1.5rem;
    }
}

.course-header-section {
    text-align: center;
    margin-bottom: 3rem;
}

.course-badge {
    background: var(--gold-bg);
    border: 1px solid var(--gold-border);
    color: var(--gold-pale);
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    padding: 0.6rem 1.6rem;
    border-radius: 50px;
    display: inline-block;
    margin-bottom: 1.6rem;
}

.course-title-main {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 6vw, 4.6rem);
    font-weight: 700;
    background: linear-gradient(135deg, #c8963e 0%, #9a6d1f 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 1rem;
}

.course-sub {
    color: var(--text-secondary);
    font-size: 1.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.course-sub a {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--gold-pale);
    text-decoration: none;
    font-weight: 500;
}

.course-sub a:hover {
    text-decoration: underline;
}

.chapter-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-card);
    margin-bottom: 2.4rem;
    overflow: hidden;
    transition: box-shadow 0.2s;
}

.chapter-card:hover {
    box-shadow: var(--shadow-card-hover);
    border-color: var(--gold-border);
}

.chapter-title {
    background: var(--bg-card-alt);
    padding: 1.6rem 2rem;
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    border-left: 5px solid var(--gold);
    font-family: var(--font-serif);
}

.chapter-list {
    list-style: none;
    padding: 0.8rem 0;
}

.chapter-list li {
    padding: 1.2rem 2rem;
    border-bottom: 1px solid var(--border-light);
    transition: background 0.2s;
}

.chapter-list li:last-child {
    border-bottom: none;
}

.chapter-list li strong {
    font-weight: 700;
    color: #2c3e2f;
    display: block;
    font-size: 1.6rem;
}

.chapter-desc {
    font-size: 1.4rem;
    color: var(--text-secondary);
    margin-top: 0.8rem;
    line-height: 1.5;
    display: block;
}

.chapter-list li:hover {
    background: var(--gold-bg);
}

.instructor-card {
    background: var(--bg-card-alt);
    border-radius: var(--radius-lg);
    padding: 2.4rem;
    text-align: center;
    border: 1px solid var(--gold-border);
}

.instructor-card h3 {
    color: var(--gold-pale);
    margin-bottom: 1.6rem;
    font-size: 2rem;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.testimonial-item {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 1.8rem;
    border: 1px solid var(--border-light);
    transition: transform 0.2s, box-shadow 0.2s;
}

.testimonial-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-card-hover);
    border-color: var(--gold-border);
}

.rating {
    color: #f5b342;
    letter-spacing: 3px;
    margin-bottom: 0.8rem;
    font-size: 1.6rem;
}

.testimonial-text {
    font-size: 1.5rem;
    line-height: 1.55;
    color: var(--text-body);
    margin-bottom: 1rem;
}

.testimonial-author {
    font-weight: 600;
    color: var(--gold-pale);
    text-align: right;
    font-size: 1.4rem;
}

.price-card {
    background: #fefdfa;
    border: 2px solid var(--gold-border);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    margin: 3rem 0 2rem;
    box-shadow: var(--shadow-cta);
}

.price-tag {
    font-size: 4.8rem;
    font-weight: 800;
    color: #2a1f0a;
    font-family: var(--font-serif);
}

.price-tag small {
    font-size: 1.6rem;
    font-weight: 400;
    color: var(--text-muted);
}

.price-original {
    text-decoration: line-through;
    color: #aaa;
    margin-right: 1.2rem;
    font-size: 2rem;
}

.btn-enroll {
    background: linear-gradient(135deg, #d4a853 0%, #b8862d 100%);
    color: white;
    font-weight: 700;
    font-size: 1.8rem;
    padding: 1.2rem 3rem;
    border-radius: 60px;
    display: inline-block;
    text-decoration: none;
    margin-top: 1.6rem;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 5px 15px rgba(184, 134, 45, 0.3);
}

.btn-enroll:hover {
    transform: translateY(-2px);
    background: linear-gradient(135deg, #e0b860 0%, #c8963e 100%);
    box-shadow: 0 8px 22px rgba(184, 134, 45, 0.4);
    color: white;
}

@media (max-width: 720px) {
    .chapter-title {
        font-size: 1.7rem;
        padding: 1.2rem 1.5rem;
    }

    .chapter-list li {
        padding: 1rem 1.5rem;
    }

    .price-tag {
        font-size: 3.6rem;
    }

    .price-original {
        font-size: 1.6rem;
    }

    .btn-enroll {
        font-size: 1.6rem;
        padding: 1rem 2rem;
    }

    .instructor-card h3 {
        font-size: 1.8rem;
    }

    .testimonial-text {
        font-size: 1.4rem;
    }
}