:root {
    --bg-deep: #0a0f1a;
    --bg-surface: #111827;
    --bg-card: #1a1f2e;
    --text-primary: #e8ecf1;
    --text-secondary: #b0b8c5;
    --text-muted: #7a8494;
    --accent-gold: #e2b96f;
    --accent-amber: #f0c674;
    --accent-blue: #5b9bd5;
    --accent-teal: #4db8a8;
    --accent-rose: #d4787c;
    --gradient-hero: linear-gradient(135deg, #0f1b35 0%, #152040 25%, #1a2745 50%, #0f1b35 100%);
    --gradient-art: linear-gradient(135deg, #e8c97a 0%, #f0d68a 20%, #d4a84b 40%, #e8c97a 55%, #c9983e 70%, #f0d68a 100%);
    --gradient-banner: linear-gradient(135deg, #1a2745 0%, #1e3255 30%, #1a3a50 60%, #162040 100%);
    --gradient-accent: linear-gradient(135deg, #5b9bd5 0%, #4db8a8 50%, #3da878 100%);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow-gold: 0 0 30px rgba(226, 185, 111, 0.25);
    --shadow-glow-blue: 0 0 30px rgba(91, 155, 213, 0.2);
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
    --font-sans: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', 'Source Code Pro', 'Noto Sans Mono SC', monospace;
    --navbar-height: 60px;
    --max-width: 1100px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    background-image:
        radial-gradient(ellipse at 20% 15%, rgba(91, 155, 213, 0.06) 0%, transparent 60%),
        radial-gradient(ellipse at 75% 30%, rgba(77, 184, 168, 0.05) 0%, transparent 55%),
        radial-gradient(ellipse at 50% 70%, rgba(226, 185, 111, 0.04) 0%, transparent 50%);
    background-attachment: fixed;
}

/* 跳过导航链接 */
.skip-link {
    position: absolute;
    top: -100px;
    left: 16px;
    z-index: 1000;
    background: var(--accent-gold);
    color: #1a1a1a;
    padding: 8px 16px;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    font-weight: 600;
    text-decoration: none;
    transition: top var(--transition-fast);
    font-size: 0.9rem;
}
.skip-link:focus {
    top: 0;
    outline: 3px solid var(--accent-amber);
    outline-offset: 2px;
}

/* 导航栏 */
.navbar {
    position: sticky;
    top: 0;
    z-index: 900;
    width: 100%;
    height: var(--navbar-height);
    background: rgba(10, 15, 26, 0.82);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-smooth), box-shadow var(--transition-smooth);
}
.navbar.scrolled {
    background: rgba(10, 15, 26, 0.94);
    box-shadow: var(--shadow-md);
    border-bottom-color: rgba(255, 255, 255, 0.1);
}
.navbar-inner {
    width: 100%;
    max-width: var(--max-width);
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.navbar-brand {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    background: var(--gradient-art);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    text-decoration: none;
    white-space: nowrap;
    transition: filter var(--transition-fast);
    filter: brightness(1);
}
.navbar-brand:hover {
    filter: brightness(1.25);
}
.navbar-links {
    display: flex;
    align-items: center;
    gap: 6px;
    list-style: none;
}
.navbar-links li {
    display: flex;
}
.navbar-links a {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 8px 16px;
    border-radius: 24px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    transition: all var(--transition-smooth);
    position: relative;
    white-space: nowrap;
}
.navbar-links a:hover,
.navbar-links a:focus-visible {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
    outline: none;
}
.navbar-links a:focus-visible {
    box-shadow: 0 0 0 3px rgba(226, 185, 111, 0.5);
}
.navbar-links a.nav-external::after {
    content: '↗';
    font-size: 0.7em;
    margin-left: 2px;
    opacity: 0.6;
    transition: opacity var(--transition-fast);
}
.navbar-links a.nav-external:hover::after {
    opacity: 1;
}
.nav-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

/* 移动端导航 */
@media (max-width: 640px) {
    .navbar-inner {
        padding: 0 14px;
    }
    .navbar-brand {
        font-size: 1rem;
        letter-spacing: 0.02em;
    }
    .navbar-links a {
        padding: 6px 10px;
        font-size: 0.85rem;
        border-radius: 20px;
        gap: 3px;
    }
    .nav-icon {
        width: 15px;
        height: 15px;
    }
    .navbar-links {
        gap: 2px;
    }
}

/* 主内容 */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 页头 */
.page-header {
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 48px 24px 28px;
    position: relative;
    overflow: hidden;
}
.page-header::before {
    content: '';
    position: absolute;
    top: -40%;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(226, 185, 111, 0.08) 0%, transparent 70%);
    pointer-events: none;
    border-radius: 50%;
}
.art-title-wrapper {
    position: relative;
    z-index: 1;
    text-align: center;
}
.art-title {
    display: inline-block;
    font-size: clamp(2.2rem, 5vw, 3.6rem);
    font-weight: 800;
    letter-spacing: 0.08em;
    line-height: 1.3;
    background: var(--gradient-art);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    text-shadow: none;
    filter: drop-shadow(0 2px 8px rgba(200, 155, 60, 0.35));
    animation: artShimmer 5s ease-in-out infinite;
    cursor: default;
    user-select: none;
    -webkit-user-select: none;
    position: relative;
}
.art-title::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 10%;
    width: 80%;
    height: 2px;
    background: var(--gradient-art);
    opacity: 0.5;
    border-radius: 2px;
    filter: blur(1px);
}
.art-subtitle {
    display: block;
    margin-top: 6px;
    font-size: 0.95rem;
    font-weight: 400;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    opacity: 0.75;
    transition: opacity var(--transition-smooth);
}
.art-title-wrapper:hover .art-subtitle {
    opacity: 1;
}

@keyframes artShimmer {
    0%, 100% { background-position: 0% 50%; }
    25% { background-position: 100% 30%; }
    50% { background-position: 100% 70%; }
    75% { background-position: 0% 70%; }
}

@media (max-width: 640px) {
    .page-header {
        padding: 32px 16px 20px;
    }
    .art-title {
        letter-spacing: 0.05em;
    }
    .art-subtitle {
        font-size: 0.8rem;
    }
}

/* 横幅/Hero */
.hero-section {
    width: 100%;
    max-width: var(--max-width);
    padding: 16px 24px 40px;
    display: flex;
    justify-content: center;
}
.hero-card {
    display: block;
    width: 100%;
    max-width: 750px;
    background: var(--gradient-banner);
    border-radius: var(--radius-lg);
    padding: 40px 36px;
    text-decoration: none;
    color: var(--text-primary);
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: var(--shadow-lg), var(--shadow-glow-blue);
    transition: all var(--transition-bounce);
    cursor: pointer;
}
.hero-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.55), 0 0 45px rgba(91, 155, 213, 0.3);
    border-color: rgba(255, 255, 255, 0.15);
}
.hero-card:focus-visible {
    outline: 3px solid var(--accent-gold);
    outline-offset: 4px;
    transform: translateY(-2px);
}
.hero-card::before {
    content: '';
    position: absolute;
    top: -60px;
    right: -60px;
    width: 220px;
    height: 220px;
    background: radial-gradient(circle, rgba(91, 155, 213, 0.2) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
    transition: all var(--transition-smooth);
}
.hero-card:hover::before {
    width: 280px;
    height: 280px;
    top: -80px;
    right: -80px;
    opacity: 1.3;
}
.hero-card::after {
    content: '';
    position: absolute;
    bottom: -40px;
    left: -40px;
    width: 160px;
    height: 160px;
    background: radial-gradient(circle, rgba(77, 184, 168, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
    transition: all var(--transition-smooth);
}
.hero-card:hover::after {
    width: 200px;
    height: 200px;
    bottom: -50px;
    left: -50px;
    opacity: 1.4;
}
.hero-badge {
    display: inline-block;
    padding: 5px 14px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.08);
    color: var(--accent-teal);
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
    border: 1px solid rgba(77, 184, 168, 0.3);
    transition: all var(--transition-smooth);
}
.hero-card:hover .hero-badge {
    background: rgba(77, 184, 168, 0.15);
    border-color: rgba(77, 184, 168, 0.5);
    box-shadow: 0 0 16px rgba(77, 184, 168, 0.2);
}
.hero-title {
    font-size: clamp(1.6rem, 3.5vw, 2.4rem);
    font-weight: 700;
    letter-spacing: 0.03em;
    margin-bottom: 10px;
    position: relative;
    z-index: 1;
    color: #ffffff;
    transition: color var(--transition-smooth);
}
.hero-description {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.6;
    position: relative;
    z-index: 1;
    max-width: 500px;
    transition: color var(--transition-smooth);
}
.hero-card:hover .hero-description {
    color: #d0d6e0;
}
.hero-arrow {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 18px;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--accent-blue);
    position: relative;
    z-index: 1;
    transition: all var(--transition-smooth);
}
.hero-arrow .arrow-icon {
    display: inline-block;
    transition: transform var(--transition-smooth);
    font-size: 1.1em;
}
.hero-card:hover .hero-arrow {
    color: #7cb8e8;
}
.hero-card:hover .hero-arrow .arrow-icon {
    transform: translateX(5px);
}

@media (max-width: 640px) {
    .hero-section {
        padding: 8px 14px 32px;
    }
    .hero-card {
        padding: 28px 20px;
        border-radius: var(--radius-md);
    }
    .hero-description {
        font-size: 0.9rem;
    }
    .hero-arrow {
        font-size: 0.85rem;
    }
}

/* 内容区域 */
.content-section {
    width: 100%;
    max-width: var(--max-width);
    padding: 20px 24px 60px;
    display: flex;
    flex-direction: column;
    gap: 32px;
}
.content-placeholder {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
    font-size: 0.95rem;
    letter-spacing: 0.03em;
    border: 2px dashed rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    transition: all var(--transition-smooth);
    cursor: default;
}
.content-placeholder:hover {
    border-color: rgba(255, 255, 255, 0.18);
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.015);
}

/* 页脚 */
.site-footer {
    width: 100%;
    background: var(--bg-surface);
    border-top: 1px solid rgba(255, 255, 255, 0.07);
    padding: 28px 24px;
    display: flex;
    justify-content: center;
    margin-top: auto;
}
.footer-inner {
    width: 100%;
    max-width: var(--max-width);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.footer-info {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 16px;
    color: var(--text-muted);
    font-size: 0.9rem;
}
.footer-info a {
    color: var(--accent-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
    font-weight: 500;
}
.footer-info a:hover {
    color: var(--accent-teal);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.footer-copy {
    color: var(--text-muted);
    font-size: 0.85rem;
    letter-spacing: 0.02em;
}
.footer-copy strong {
    color: var(--text-secondary);
    font-weight: 600;
}

@media (max-width: 640px) {
    .site-footer {
        padding: 20px 14px;
    }
    .footer-inner {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }
    .footer-info {
        justify-content: center;
        font-size: 0.82rem;
        gap: 10px;
    }
    .footer-copy {
        font-size: 0.78rem;
    }
}

/* 淡入动画 */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}
.fade-in-up-delay-1 {
    transition-delay: 0.1s;
}
.fade-in-up-delay-2 {
    transition-delay: 0.2s;
}
.fade-in-up-delay-3 {
    transition-delay: 0.3s;
}

/* 焦点可见样式 */
:focus-visible {
    outline: 3px solid var(--accent-gold);
    outline-offset: 2px;
    border-radius: 4px;
}

/* 选择文本 */
::selection {
    background: rgba(226, 185, 111, 0.3);
    color: #fff;
}
::-moz-selection {
    background: rgba(226, 185, 111, 0.3);
    color: #fff;
}

/* 滚动条 */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-deep);
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.12);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.22);
}