/* 基础样式 */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;

    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;

    --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);

    --border-radius: 12px;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --bg-primary: #1e293b;
    --bg-secondary: #334155;
    --bg-tertiary: #475569;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #475569;
}

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

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

/* 导航栏 */
.navbar {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

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

.theme-btn {
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
}

.theme-btn:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

/* 主内容 */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

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

/* 英雄区域 */
.hero-section {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius);
    padding: 4rem 2rem;
    text-align: center;
    color: white;
    margin-bottom: 3rem;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-content p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

/* 按钮样式 */
.btn-primary, .btn-secondary, .btn-success, .btn-info {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

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

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

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

.btn-secondary:hover {
    background: var(--bg-tertiary);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

/* 表单控件 */
select, input {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

select:focus, input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* 壁纸展示 */
.wallpaper-display {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
}

.display-controls {
    margin-bottom: 2rem;
}

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

.wallpaper-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
}

.wallpaper-frame {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    overflow: hidden;
    position: relative;
    box-shadow: var(--shadow);
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#current-wallpaper {
    max-width: 100%;
    max-height: 70vh;
    object-fit: contain;
    display: none;
}

.wallpaper-loading {
    text-align: center;
    color: var(--text-secondary);
}

.wallpaper-loading i {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.wallpaper-info {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.wallpaper-info h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.info-grid {
    display: grid;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.info-item {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.info-item label {
    font-weight: 600;
    color: var(--text-secondary);
}

.info-item span {
    color: var(--text-primary);
}

.wallpaper-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.wallpaper-actions button {
    flex: 1;
    min-width: 120px;
}

/* 网格布局 */
.categories-grid, .wallpapers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* 分类卡片 */
.category-card {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.category-card.hot {
    border-color: var(--warning-color);
}

.category-card.hot::before {
    content: "🔥";
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
}

.category-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 壁纸卡片 */
.wallpaper-card {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
}

.wallpaper-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.wallpaper-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--bg-tertiary);
}

.wallpaper-card-content {
    padding: 1rem;
}

.wallpaper-card h4 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-size: 0.9rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.wallpaper-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* 加载状态 */
.loading {
    background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-tertiary) 50%, var(--bg-secondary) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.category-loading, .wallpaper-loading {
    height: 120px;
    border-radius: var(--border-radius);
}

/* 部分头部 */
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* 控制组 */
.control-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.control-group label {
    font-weight: 600;
    color: var(--text-secondary);
}

.random-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
}

.modal-content {
    position: relative;
    margin: 2% auto;
    width: 90%;
    max-width: 1200px;
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    overflow: hidden;
    animation: modalAppear 0.3s ease;
}

@keyframes modalAppear {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

.close-modal {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 2rem;
    color: white;
    cursor: pointer;
    z-index: 10;
    background: rgba(0, 0, 0, 0.5);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

#modal-image {
    width: 100%;
    max-height: 80vh;
    object-fit: contain;
}

.modal-actions {
    padding: 1rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* 提示框 */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    background: var(--bg-primary);
    color: var(--text-primary);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    z-index: 3000;
    transform: translateY(100px);
    opacity: 0;
    transition: var(--transition);
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

.toast.loading {
    background: var(--warning-color);
    color: white;
}

.toast.success {
    background: var(--success-color);
    color: white;
}

.toast.error {
    background: var(--danger-color);
    color: white;
}

/* 占位文本 */
.placeholder-text {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
    grid-column: 1 / -1;
}

.placeholder-text i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.load-more-container {
    text-align: center;
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }

    .nav-link {
        padding: 0.5rem;
        font-size: 0.875rem;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .wallpaper-container {
        grid-template-columns: 1fr;
    }

    .categories-grid, .wallpapers-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }

    .random-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-search {
        flex-direction: column;
    }

    .resolution-controls {
        flex-direction: column;
        align-items: stretch;
    }
}

@media (max-width: 480px) {
    .categories-grid, .wallpapers-grid {
        grid-template-columns: 1fr;
    }

    .modal-content {
        margin: 5% auto;
        width: 95%;
    }
}