/**
 * Landing V3 - 现代化设计系统
 * 从 landing-v3.html 提取
 * 创建时间: 2026-06-15
 */

/* ========== DESIGN TOKENS ========== */
:root {
    /* Core palette - warm coral + cool teal */
    --coral: #FF6B4A;
    --coral-light: #FF8A6B;
    --coral-dark: #E5523A;
    --teal: #2EC4B6;
    --teal-light: #3EDDD0;
    --sunny: #FFD166;
    --purple: #9B5DE5;
    --pink: #F15BB5;
    
    /* Neutrals with warmth */
    --gray-50: #FEF9F5;
    --gray-100: #FDF2EB;
    --gray-200: #F5E6D8;
    --gray-300: #E8D5C4;
    --gray-400: #C4B0A0;
    --gray-500: #8A7A6B;
    --gray-600: #5C5045;
    --gray-700: #3D3430;
    --gray-800: #2A2320;
    --gray-900: #1A1512;
    
    /* Semantic */
    --bg: var(--gray-50);
    --text: var(--gray-800);
    --text-secondary: var(--gray-500);
    --accent: var(--coral);
    --accent-alt: var(--teal);
    
    /* Typography - 使用系统字体，快速加载 */
    --font-display: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    
    /* Spacing - dramatic scale */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;
    
    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

[data-theme="dark"] {
    --bg: var(--gray-900);
    --text: var(--gray-100);
    --text-secondary: var(--gray-400);
}

/* ========== RESET & BASE ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ========== TYPOGRAPHY ========== */
h1, h2, h3 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

/* ========== LAYOUT ========== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========== NAV ========== */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    padding: 16px 0;
    transition: all 0.3s var(--ease-out);
}

.nav.scrolled {
    background: rgba(254, 249, 245, 0.9);
    backdrop-filter: blur(12px);
    box-shadow: 0 1px 0 var(--gray-200);
    padding: 10px 0;
}

[data-theme="dark"] .nav.scrolled {
    background: rgba(26, 21, 18, 0.9);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: var(--coral);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: transform 0.3s var(--ease-spring);
}

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

.nav-logo span {
    color: var(--coral);
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--coral);
    transition: width 0.3s var(--ease-out);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 12px;
    font-family: var(--font-display);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
}

.btn-primary {
    background: var(--coral);
    color: white;
    box-shadow: 0 4px 20px rgba(255, 107, 74, 0.3);
}

.btn-primary:hover {
    background: var(--coral-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255, 107, 74, 0.4);
    color: white;
}

.btn-outline {
    background: transparent;
    color: var(--text);
    border: 2px solid var(--gray-300);
}

.btn-outline:hover {
    border-color: var(--coral);
    color: var(--coral);
    transform: translateY(-2px);
}

/* ========== HERO ========== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding: 120px 24px 80px;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(255, 107, 74, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(46, 196, 182, 0.06) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content {
    position: relative;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--coral);
    color: white;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 24px;
    animation: fadeInUp 0.6s var(--ease-out);
}

.hero h1 {
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 700;
    color: var(--text);
    margin-bottom: 24px;
    animation: fadeInUp 0.6s 0.1s var(--ease-out) both;
}

.hero h1 .accent {
    color: var(--coral);
    position: relative;
    display: inline-block;
}

.hero h1 .accent::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: -4px;
    right: -4px;
    height: 12px;
    background: rgba(255, 107, 74, 0.15);
    border-radius: 6px;
    z-index: -1;
}

.hero-sub {
    font-size: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 40px;
    max-width: 500px;
    animation: fadeInUp 0.6s 0.2s var(--ease-out) both;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    animation: fadeInUp 0.6s 0.3s var(--ease-out) both;
}

/* Hero visual */
.hero-visual {
    position: relative;
    animation: fadeInRight 0.8s 0.2s var(--ease-out) both;
}

.hero-card-stack {
    position: relative;
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
    aspect-ratio: 3/4;
}

.hero-card {
    position: absolute;
    width: 100%;
    background: white;
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.08);
    border: 2px solid var(--gray-200);
    transition: transform 0.4s var(--ease-out);
}

[data-theme="dark"] .hero-card {
    background: var(--gray-800);
    border-color: var(--gray-700);
}

.hero-card:nth-child(1) {
    top: 0;
    left: 0;
    transform: rotate(-6deg);
    z-index: 3;
}

.hero-card:nth-child(2) {
    top: 20px;
    left: 10px;
    transform: rotate(3deg);
    z-index: 2;
}

.hero-card:nth-child(3) {
    top: 40px;
    left: -5px;
    transform: rotate(-2deg);
    z-index: 1;
}

.hero-card:hover {
    transform: rotate(0deg) translateY(-8px);
    box-shadow: 0 30px 80px rgba(0,0,0,0.12);
}

.hero-card-tag {
    display: inline-block;
    padding: 4px 12px;
    background: var(--coral);
    color: white;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.hero-card-title {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 8px;
}

.hero-card-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ========== SECTION COMMON ========== */
.section {
    padding: var(--space-xl) 24px;
}

.section-header {
    margin-bottom: var(--space-lg);
}

.section-tag {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--coral);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--text);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
}

/* ========== STORIES GRID ========== */
.stories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 32px;
}

.story-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    border: 2px solid transparent;
    transition: all 0.4s var(--ease-out);
    cursor: pointer;
}

[data-theme="dark"] .story-card {
    background: var(--gray-800);
}

.story-card:hover {
    transform: translateY(-8px);
    border-color: var(--coral);
    box-shadow: 0 20px 60px rgba(255, 107, 74, 0.15);
}

.story-card-cover {
    height: 180px;
    position: relative;
    overflow: hidden;
}

.story-card-cover.scifi {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.story-card-cover.fantasy {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.story-card-cover.mystery {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.story-card-cover-inner {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
}

.story-card-body {
    padding: 24px;
}

.story-card-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
}

.story-card-category {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--coral);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.story-card-ai {
    font-size: 0.75rem;
    padding: 2px 8px;
    background: rgba(46, 196, 182, 0.1);
    color: var(--teal);
    border-radius: 4px;
    font-weight: 600;
}

.story-card-title {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 8px;
    line-height: 1.3;
}

.story-card-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 16px;
}

.story-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px solid var(--gray-200);
}

[data-theme="dark"] .story-card-footer {
    border-color: var(--gray-700);
}

.story-card-author {
    display: flex;
    align-items: center;
    gap: 8px;
}

.story-card-avatar {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--coral);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
}

.story-card-stats {
    display: flex;
    gap: 12px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ========== CATEGORIES ========== */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 16px;
}

.category-pill {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 24px 16px;
    background: white;
    border-radius: 16px;
    border: 2px solid var(--gray-200);
    text-decoration: none;
    transition: all 0.3s var(--ease-out);
    cursor: pointer;
}

[data-theme="dark"] .category-pill {
    background: var(--gray-800);
    border-color: var(--gray-700);
}

.category-pill:hover {
    border-color: var(--coral);
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(255, 107, 74, 0.12);
}

.category-pill-icon {
    font-size: 2rem;
}

.category-pill-label {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text);
}

.category-pill-count {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* ========== FEATURES ========== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 32px;
}

.feature-card {
    padding: 32px;
    background: white;
    border-radius: 20px;
    border: 2px solid var(--gray-200);
    transition: all 0.4s var(--ease-out);
}

[data-theme="dark"] .feature-card {
    background: var(--gray-800);
    border-color: var(--gray-700);
}

.feature-card:hover {
    border-color: var(--teal);
    transform: translateY(-4px);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.feature-icon.ai {
    background: rgba(255, 107, 74, 0.1);
}

.feature-icon.community {
    background: rgba(46, 196, 182, 0.1);
}

.feature-icon.speed {
    background: rgba(255, 209, 102, 0.1);
}

.feature-icon.security {
    background: rgba(155, 93, 229, 0.1);
}

.feature-title {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 8px;
}

.feature-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========== STATS ========== */
.stats-banner {
    background: var(--coral);
    padding: var(--space-lg) 24px;
    position: relative;
    overflow: hidden;
}

.stats-banner::before {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.stats-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    position: relative;
    z-index: 1;
}

.stat-item {
    text-align: center;
    color: white;
}

.stat-number {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* ========== PRICING ========== */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    max-width: 1000px;
    margin: 0 auto;
}

.pricing-card {
    background: white;
    border-radius: 24px;
    padding: 40px 32px;
    border: 2px solid var(--gray-200);
    transition: all 0.4s var(--ease-out);
    position: relative;
}

[data-theme="dark"] .pricing-card {
    background: var(--gray-800);
    border-color: var(--gray-700);
}

.pricing-card.popular {
    border-color: var(--coral);
    box-shadow: 0 20px 60px rgba(255, 107, 74, 0.15);
}

.pricing-card.popular::before {
    content: '最受欢迎';
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--coral);
    color: white;
    padding: 6px 20px;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 700;
    font-family: var(--font-display);
}

.pricing-name {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.pricing-price {
    font-family: var(--font-display);
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--text);
    line-height: 1;
    margin-bottom: 8px;
}

.pricing-period {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.pricing-features {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 40px;
}

.pricing-features li {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.95rem;
    color: var(--text);
}

.pricing-features li::before {
    content: '✓';
    width: 24px;
    height: 24px;
    background: rgba(46, 196, 182, 0.1);
    color: var(--teal);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
    flex-shrink: 0;
}

/* ========== FOOTER ========== */
.footer {
    background: var(--gray-800);
    color: var(--gray-300);
    padding: var(--space-lg) 24px var(--space-md);
}

[data-theme="dark"] .footer {
    background: var(--gray-900);
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: var(--space-lg);
}

.footer-brand {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 700;
    color: white;
    margin-bottom: 16px;
}

.footer-desc {
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 20px;
}

.footer-title {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 20px;
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: var(--gray-400);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: var(--coral);
}

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--gray-700);
    text-align: center;
    font-size: 0.9rem;
    color: var(--gray-500);
}

/* ========== THEME TOGGLE ========== */
.theme-toggle {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    border: 2px solid var(--gray-200);
    background: var(--bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.3s;
}

.theme-toggle:hover {
    border-color: var(--coral);
}

/* ========== BACK TO TOP ========== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 14px;
    background: var(--coral);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    box-shadow: 0 8px 30px rgba(255, 107, 74, 0.3);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.4s var(--ease-out);
    z-index: 50;
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
}

/* ========== ANIMATIONS ========== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(40px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s var(--ease-out);
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero-inner {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
    
    .stories-grid {
        grid-template-columns: 1fr;
    }
}