/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #f59e0b;
    --radius: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}

/* Light theme (fallback) */
:root {
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* Dark theme (default) */
body {
    --text-color: #f9fafb;
    --text-light: #d1d5db;
    --bg-color: #111827;
    --bg-light: #1f2937;
    --border-color: #374151;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

/* Light theme override */
body.light-theme {
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: 1rem;
    font-weight: 600;
    line-height: 1.2;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-light);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: var(--bg-light);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--text-color);
    color: white;
}

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

.btn-outline:hover {
    background-color: var(--primary-color);
    color: white;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Header/Hero */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0 6rem;
    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 1000 1000"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="25" cy="75" r="1" fill="white" opacity="0.05"/><circle cx="75" cy="25" r="1" fill="white" opacity="0.05"/></pattern></defs><rect width="1000" height="1000" fill="url(%23grain)"/></svg>');
    pointer-events: none;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.emoji {
    font-size: 2.5rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

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

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.8;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Navigation */
.navbar {
    background: rgba(17, 24, 39, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.light-theme .navbar {
    background: rgba(255, 255, 255, 0.95);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
    border-radius: 1px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: var(--transition);
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle .theme-btn {
    background: none;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-color);
    transition: var(--transition);
}

.theme-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.language-selector select {
    background: var(--bg-light);
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    padding: 0.5rem;
    color: var(--text-color);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
}

.language-selector select:hover,
.language-selector select:focus {
    border-color: var(--primary-color);
    outline: none;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar .container {
        flex-wrap: wrap;
    }
    
    .nav-controls {
        order: -1;
        width: 100%;
        justify-content: flex-end;
        margin-bottom: 1rem;
    }
    
    .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        gap: 1rem;
        margin-top: 1rem;
        padding-top: 1rem;
        border-top: 1px solid var(--border-color);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .nav-toggle {
        display: flex;
    }
}

/* Sections */
section {
    padding: 4rem 0;
}

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

.section-title {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.section-description {
    max-width: 600px;
    margin: 0 auto;
    font-size: 1.125rem;
}

/* Filter Controls */
.filter-controls {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
    align-items: center;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-group label {
    font-weight: 500;
    color: var(--text-light);
}

.filter-group select {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: white;
    font-size: 0.875rem;
}

.search-group {
    position: relative;
    display: flex;
    align-items: center;
}

.search-group input {
    padding: 0.5rem 2.5rem 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 0.875rem;
    width: 250px;
}

.search-group i {
    position: absolute;
    right: 0.75rem;
    color: var(--text-light);
    pointer-events: none;
}

/* Cases Grid */
.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.case-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s ease forwards;
}

.case-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.case-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

.case-card:hover .case-image {
    transform: scale(1.05);
}

.case-content {
    padding: 1.5rem;
}

.case-title {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.case-number {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius);
    font-size: 0.75rem;
    font-weight: 600;
}

.case-author {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.case-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.case-tag {
    background: var(--bg-light);
    color: var(--primary-color);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius);
    font-size: 0.75rem;
    font-weight: 500;
}

.case-actions {
    display: flex;
    gap: 0.5rem;
}

.case-action {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: none;
    color: var(--text-light);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
}

.case-action:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Load More */
.load-more-container {
    text-align: center;
}

/* About Section */
.about-section {
    background: var(--bg-light);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.about-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.about-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
}

/* Contribute Section */
.contribute-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.contribute-step {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow);
    position: relative;
    transition: var(--transition);
}

.contribute-step:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.step-number {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
}

/* Footer */
.footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    color: white;
    font-size: 1.25rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.footer-bottom a {
    color: var(--accent-color);
    text-decoration: none;
}

.footer-bottom a:hover {
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero {
        padding: 2rem 0 4rem;
    }

    .hero-title {
        font-size: 2.5rem;
        flex-direction: column;
        gap: 0.5rem;
    }

    .hero-stats {
        gap: 1rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .nav-links {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .filter-controls {
        flex-direction: column;
        gap: 1rem;
    }

    .search-group input {
        width: 200px;
    }

    .cases-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .about-grid,
    .contribute-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 2rem; }

    .hero-title {
        font-size: 2rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 0.5rem;
    }

    .filter-controls {
        align-items: stretch;
    }

    .search-group input {
        width: 100%;
    }
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 0;
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 800px;
    position: relative;
    animation: slideIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    position: absolute;
    right: 20px;
    top: 15px;
    color: var(--text-light);
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    z-index: 1;
}

.close:hover {
    color: var(--text-color);
}

.modal-body {
    padding: 2rem;
    max-height: 70vh;
    overflow-y: auto;
}

.modal-image {
    width: 100%;
    border-radius: var(--radius);
    margin-bottom: 1rem;
}

.modal-title {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.modal-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.modal-meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-light);
    font-size: 0.875rem;
}

.modal-prompt {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: var(--radius);
    margin: 1rem 0;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.875rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-word;
}

/* Scroll to Top Button */
.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 100;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}