/* ========================================
   宇宙天文图库 - 简约现代风格 v5.0
   华丽简约 | 紧凑整齐 | 清晰提示
   ======================================== */

:root {
    /* 配色 - Space Tech风格 */
    --bg-primary: #0B0B10;
    --bg-secondary: #111318;
    --bg-tertiary: #181B22;
    --bg-card: #1A1D26;
    --bg-hover: #22262F;
    
    /* 强调色 */
    --accent-primary: #3B82F6;
    --accent-secondary: #94A3B8;
    --accent-gold: #F59E0B;
    --accent-cyan: #22D3EE;
    
    /* 文字色 */
    --text-primary: #F8FAFC;
    --text-secondary: #CBD5E1;
    --text-muted: #64748B;
    
    /* 边框 */
    --border-default: #1E293B;
    --border-hover: #334155;
    
    /* 字体 */
    --font-display: 'Space Grotesk', 'Noto Sans SC', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --font-body: 'Noto Sans SC', sans-serif;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    
    /* 过渡 */
    --transition-fast: 150ms ease-out;
    --transition-normal: 200ms ease-out;
    
    /* 间距 - 增大基础单位 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
}

/* ========================================
   基础样式
   ======================================== */

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    height: 100%;
}

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100%;
    overflow-x: hidden;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* 尊重用户的动画偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ========================================
   星空背景 - 简化版
   ======================================== */

#starfield {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    background: var(--bg-primary);
}

.star {
    position: absolute;
    background: white;
    border-radius: 50%;
    animation: twinkle var(--duration, 4s) ease-in-out infinite;
    animation-delay: var(--delay, 0s);
}

@keyframes twinkle {
    0%, 100% { opacity: var(--opacity, 0.15); }
    50% { opacity: 0.4; }
}

/* ========================================
   主容器
   ======================================== */

.main-container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 1rem;
}

/* 单屏显示模式 */
.page-single-screen {
    height: 100vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.page-single-screen .main-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    padding: 1rem;
}

/* Index上下布局 */
.index-layout {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    padding: 0 1rem;
}

/* ========================================
   头部区域
   ======================================== */

.hero-section {
    text-align: center;
    padding: var(--spacing-lg) 0;
}

.logo-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.main-title {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.title-logo {
    flex-shrink: 0;
    height: 1.8em;
    width: 1.8em;
    object-fit: contain;
    padding: 0.25em;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 50%;
    backdrop-filter: blur(4px);
}

.subtitle {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

/* ========================================
   搜索区域
   ======================================== */

.search-section {
    padding: var(--spacing-md) 0;
}

.search-container {
    max-width: 700px;
    margin: 0 auto;
}

.search-box {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    transition: border-color var(--transition-fast);
}

.search-box:focus-within {
    border-color: var(--accent-primary);
}

.date-picker {
    flex: 1;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: border-color var(--transition-fast);
}

.date-picker:hover {
    border-color: var(--border-hover);
}

.date-picker:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.search-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--accent-primary);
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-xl);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    color: white;
    cursor: pointer;
    transition: opacity var(--transition-fast);
}

.search-btn:hover {
    opacity: 0.9;
}

.search-btn:active {
    opacity: 0.8;
}

.search-btn svg {
    width: 16px;
    height: 16px;
}

.quick-btns {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    flex-wrap: wrap;
}

.quick-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.quick-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

/* ========================================
   区块标题
   ======================================== */

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

.section-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.section-desc {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: var(--spacing-sm);
}

/* ========================================
   随机图片区域
   ======================================== */

.featured-section {
    padding: var(--spacing-md) 0;
}

.featured-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

/* 4列网格 */
.featured-grid-4 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.loading-placeholder {
    grid-column: 1 / -1;
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-muted);
    font-size: 1rem;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto var(--spacing-lg);
    border: 3px solid var(--border-default);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* 图片卡片 */
.image-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: pointer;
    transition: border-color var(--transition-fast);
}

.image-card:hover {
    border-color: var(--accent-primary);
}

.card-img-wrap {
    position: relative;
    min-height: 280px;
    max-height: 400px;
    overflow: hidden;
    background: var(--bg-tertiary);
}

.card-img {
    width: 100%;
    min-height: 280px;
    object-fit: cover;
    transition: transform 0.3s ease-out;
}

.image-card:hover .card-img {
    transform: scale(1.02);
}

.card-date-badge {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    background: rgba(11, 11, 16, 0.85);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* 图片上叠加的文字信息 */
.card-overlay-info {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-lg) var(--spacing-md) var(--spacing-md);
    background: linear-gradient(transparent, rgba(11, 11, 16, 0.95));
}

.card-overlay-info .card-title {
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-overlay-info .card-excerpt {
    color: var(--text-secondary);
    font-size: 0.85rem;
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-body {
    padding: var(--spacing-lg);
}

.card-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-excerpt {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-footer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--accent-primary);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-default);
}

/* ========================================
   档案区域
   ======================================== */

.archive-section {
    padding: var(--spacing-md) 0;
}

.archive-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.archive-select {
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-md) 2rem var(--spacing-md) var(--spacing-lg);
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: var(--text-primary);
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748B' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    min-width: 130px;
    transition: border-color var(--transition-fast);
}

.archive-select:hover {
    border-color: var(--border-hover);
}

.archive-select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.archive-select:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.archive-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(65px, 1fr));
    gap: var(--spacing-sm);
    max-height: 120px;
    overflow-y: auto;
}

.archive-link {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.archive-link:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

/* ========================================
   页脚
   ======================================== */

.footer {
    padding: var(--spacing-xl) var(--spacing-xl);
    text-align: center;
    border-top: 1px solid var(--border-default);
    background: var(--bg-primary);
    position: relative;
    z-index: 10;
}

.footer-content {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-muted);
    text-align: center;
}

.footer-content a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-content a:hover {
    color: var(--accent-cyan);
}

/* ========================================
   单屏模式适配
   ======================================== */

.page-single-screen .hero-section {
    padding: var(--spacing-md) 0;
}

.page-single-screen .main-title {
    font-size: 1.5rem;
}

.page-single-screen .subtitle {
    font-size: 0.85rem;
}

.page-single-screen .search-section {
    padding: var(--spacing-sm) 0;
}

.page-single-screen .search-box {
    padding: var(--spacing-sm) var(--spacing-md);
    gap: var(--spacing-sm);
}

.page-single-screen .date-picker {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9rem;
}

.page-single-screen .search-btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.95rem;
}

.page-single-screen .quick-btns {
    margin-top: var(--spacing-md);
    gap: var(--spacing-sm);
}

.page-single-screen .quick-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.85rem;
}

.page-single-screen .featured-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    padding: var(--spacing-sm) 0;
    min-height: 0;
}

.page-single-screen .section-header {
    margin-bottom: var(--spacing-md);
    flex-shrink: 0;
}

.page-single-screen .section-title {
    font-size: 1.1rem;
}

.page-single-screen .section-desc {
    font-size: 0.85rem;
}

.page-single-screen .featured-grid-4 {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
}

.page-single-screen .image-card .card-img-wrap {
    aspect-ratio: 4/3;
    min-height: auto;
    max-height: none;
}

.page-single-screen .image-card .card-img {
    height: 100%;
    min-height: auto;
}

.page-single-screen .archive-section {
    flex-shrink: 0;
    padding: var(--spacing-sm) 0 0;
}

.page-single-screen .archive-controls {
    margin-bottom: var(--spacing-md);
}

.page-single-screen .archive-select {
    padding: var(--spacing-sm) 1.75rem var(--spacing-sm) var(--spacing-md);
    font-size: 0.85rem;
    min-width: 120px;
}

.page-single-screen .archive-grid {
    max-height: 80px;
}

/* ========================================
   响应式设计
   ======================================== */

@media (max-width: 768px) {
    .main-container {
        padding: var(--spacing-lg);
    }
    
    .main-title {
        font-size: 1.5rem;
    }
    
    .featured-grid-4 {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
    
    .search-box {
        flex-wrap: wrap;
    }
    
    .date-picker {
        min-width: 100%;
        order: -1;
    }
    
    .search-btn {
        order: 1;
    }
}

@media (max-width: 480px) {
    .featured-grid-4 {
        grid-template-columns: 1fr;
    }
    
    .quick-btns {
        gap: var(--spacing-sm);
    }
    
    .quick-btn {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.85rem;
    }
}

/* ========================================
   滚动条样式
   ======================================== */

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-hover);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ========================================
   选择框样式
   ======================================== */

::selection {
    background: var(--accent-primary);
    color: white;
}

/* ========================================
   焦点样式
   ======================================== */

:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}