/* AI Experience Lab - Modern Tech Style */
:root {
    /* AI Tech Color Palette */
    --ai-primary: #00d4ff;
    --ai-secondary: #0099cc;
    --ai-accent: #6366f1;
    --ai-neon: #00ffaa;
    --dark-bg: #0a0a0a;
    --dark-card: #111111;
    --dark-surface: #1a1a1a;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #707070;
    --border-glow: rgba(0, 212, 255, 0.3);
    --shadow-neon: 0 0 20px rgba(0, 212, 255, 0.2);
    --shadow-soft: 0 4px 20px rgba(0, 0, 0, 0.3);
    --gradient-ai: linear-gradient(135deg, var(--ai-primary), var(--ai-accent));
    --gradient-dark: linear-gradient(135deg, var(--dark-bg), var(--dark-surface));
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #e8e8e8;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a2e 50%, #16213e 100%);
    min-height: 100vh;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    background: rgba(26, 26, 46, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    padding: 1rem 0;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.logo {
    font-size: 1.8rem;
    font-weight: 800;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-menu a {
    color: #e8e8e8;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-menu a:hover {
    color: #00d4ff;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    transition: width 0.3s ease;
}

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

/* Hero Section */
.hero {
    padding: 6rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(0,212,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    position: relative;
    z-index: 1;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

.hero h1 {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b, #4ecdc4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: glow 3s ease-in-out infinite alternate;
}

@keyframes glow {
    from { filter: drop-shadow(0 0 10px rgba(0, 212, 255, 0.3)); }
    to { filter: drop-shadow(0 0 20px rgba(255, 107, 107, 0.3)); }
}

.hero p {
    font-size: 1.3rem;
    color: #b8b8b8;
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.stat-item {
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1), rgba(255, 107, 107, 0.1));
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 212, 255, 0.3);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #b8b8b8;
    font-weight: 500;
}

.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 10px 30px rgba(0, 212, 255, 0.3);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(0, 212, 255, 0.4);
}

/* Characters Section */
.characters-section {
    padding: 6rem 0;
    background: rgba(255, 255, 255, 0.02);
}

.characters-section h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.characters-section p {
    text-align: center;
    color: #b8b8b8;
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.character-nav {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.character-card {
    background: linear-gradient(135deg, rgba(26, 26, 46, 0.8), rgba(22, 33, 62, 0.6));
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.character-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

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

.character-card:hover {
    transform: translateY(-10px);
    border-color: rgba(0, 212, 255, 0.3);
    box-shadow: 0 20px 40px rgba(0, 212, 255, 0.2);
}

.character-avatar {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.character-name {
    font-size: 1.3rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 0.5rem;
}

.character-role {
    color: #00d4ff;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.character-location {
    color: #b8b8b8;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.article-count {
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    display: inline-block;
}

/* Search Section */
.search-section {
    padding: 4rem 0;
    background: rgba(0, 0, 0, 0.3);
}

.search-container {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: 0 2rem;
}

.search-section h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #ffffff;
}

.search-section p {
    color: #b8b8b8;
    margin-bottom: 2rem;
}

.search-form {
    position: relative;
    margin: 2rem 0;
}

.search-input {
    width: 100%;
    padding: 1.2rem 4rem 1.2rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 50px;
    color: #ffffff;
    font-size: 1.1rem;
    outline: none;
    transition: all 0.3s ease;
    backdrop-filter: blur(20px);
}

.search-input::placeholder {
    color: #b8b8b8;
}

.search-input:focus {
    border-color: #00d4ff;
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
}

.search-btn {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.search-btn:hover {
    transform: translateY(-50%) scale(1.1);
}

.filter-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.filter-tab {
    background: rgba(255, 255, 255, 0.1);
    color: #b8b8b8;
    padding: 0.8rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    backdrop-filter: blur(20px);
}

.filter-tab.active,
.filter-tab:hover {
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    border-color: transparent;
}

.search-results-info {
    color: #00d4ff;
    font-weight: 600;
    margin: 1rem 0;
}

/* Articles Section */
.articles-section {
    padding: 0 0.5rem; /* 进一步减少边距到0.5rem */
}

.articles-section h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 3rem;
    color: #ffffff;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
    max-width: none; /* 移除最大宽度限制，保持满屏 */
}

.article-card {
    background: linear-gradient(135deg, rgba(26, 26, 46, 0.9), rgba(22, 33, 62, 0.7));
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    overflow: hidden;
    transition: all 0.3s ease;
    position: relative;
}

.article-card:hover {
    transform: translateY(-10px);
    border-color: rgba(0, 212, 255, 0.3);
    box-shadow: 0 20px 40px rgba(0, 212, 255, 0.2);
}

.article-thumbnail {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.article-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.article-card:hover .article-thumbnail img {
    transform: scale(1.05);
}

.article-content-card {
    padding: 1.5rem;
}

.article-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    line-height: 1.4;
}

.article-title a {
    color: #ffffff;
    text-decoration: none;
    transition: color 0.3s ease;
}

.article-title a:hover {
    color: #00d4ff;
}

.article-excerpt {
    color: #b8b8b8;
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.article-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.article-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.article-tag {
    background: rgba(0, 212, 255, 0.2);
    color: #00d4ff;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

.article-difficulty {
    color: #ff6b6b;
    font-weight: 600;
    font-size: 0.9rem;
    margin-right: 0.5rem;
}

.reading-time {
    color: #b8b8b8;
    font-size: 0.8rem;
}

.article-footer {
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.read-more {
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    padding: 0.6rem 1.5rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: inline-block;
}

.read-more:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(0, 212, 255, 0.3);
}

.load-more {
    background: linear-gradient(135deg, #00d4ff, #ff6b6b);
    color: white;
    border: none;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    margin: 3rem auto;
    display: block;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.load-more:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(0, 212, 255, 0.3);
}

.no-results {
    text-align: center;
    padding: 3rem;
    color: #b8b8b8;
    font-size: 1.1rem;
}

/* Footer */
.footer {
    background: rgba(0, 0, 0, 0.5);
    padding: 3rem 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer p {
    color: #b8b8b8;
    margin-bottom: 0.5rem;
}

/* Container and Layout - 满屏设计但卡片有边距 */
.hero-container,
.search-container,
.characters-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .stats-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    
    .character-nav {
        grid-template-columns: 1fr;
    }
    
    .articles-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .filter-tabs {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .article-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.8rem;
    }
    
    .articles-section,
    .hero-container,
    .search-container,
    .characters-section {
        padding: 0 0.75rem; /* 平板设备减少边距 */
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .stats-container {
        grid-template-columns: 1fr;
    }
    
    .articles-section,
    .hero-container,
    .search-container,
    .characters-section {
        padding: 0 0.5rem; /* 手机设备进一步减少边距 */
    }
    
    .filter-tabs {
        grid-template-columns: 1fr;
    }
}

/* Smooth animations */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

/* Loading animation */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.article-card {
    animation: fadeIn 0.6s ease-out;
}

/* Parallax effect for hero */
.hero {
    background-attachment: fixed;
    background-size: cover;
    background-position: center;
}