/* ========================
   快看科技快讯 - 样式文件
   科技蓝主题 + 卡片居中布局
   ======================== */

:root {
    /* 科技蓝主色调 */
    --primary-color: #165DFF;
    --primary-light: #4080FF;
    --primary-dark: #0D3ED9;
    --accent-orange: #FF6B00;
    --accent-red: #FF3000;
    
    /* 背景色 */
    --bg-main: #0A1628;
    --bg-card: #12203A;
    --bg-card-hover: #1A2B4A;
    
    /* 文字色 */
    --text-white: #FFFFFF;
    --text-gray: #8B95A5;
    --text-light: #B8C5D6;
    
    /* 间距 */
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* 卡片尺寸 */
    --card-max-width: 480px;
    --poster-height: 280px;
}

/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-main);
    color: var(--text-white);
    line-height: 1.5;
}

/* ========================
   突发置顶条
   ======================== */
.urgent-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 44px;
    background: linear-gradient(135deg, var(--accent-red) 0%, #FF4D4F 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: urgentPulse 2s ease-in-out infinite;
}

@keyframes urgentPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.85; }
}

.urgent-content {
    display: flex;
    align-items: center;
    gap: 8px;
}

.urgent-icon {
    font-size: 16px;
    animation: flash 1s ease-in-out infinite;
}

@keyframes flash {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.7; transform: scale(1.1); }
}

.urgent-text {
    font-size: 14px;
    font-weight: 500;
    color: #FFFFFF;
    letter-spacing: 0.5px;
}

/* ========================
   顶部导航栏
   ======================== */
.nav-header {
    position: fixed;
    top: 44px;
    left: 0;
    right: 0;
    height: 56px;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(20px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-lg);
    z-index: 999;
    border-bottom: 1px solid rgba(22, 93, 255, 0.2);
}

.nav-left .logo {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    font-size: 24px;
    color: var(--primary-color);
    animation: glow 2s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { filter: drop-shadow(0 0 4px var(--primary-color)); }
    50% { filter: drop-shadow(0 0 12px var(--primary-color)); }
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-center .mode-switch {
    display: flex;
    background: rgba(22, 93, 255, 0.15);
    border-radius: var(--radius-lg);
    padding: 4px;
}

.mode-btn {
    width: 40px;
    height: 32px;
    border: none;
    background: transparent;
    color: var(--text-gray);
    cursor: pointer;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.mode-btn.active {
    background: var(--primary-color);
    color: var(--text-white);
    box-shadow: 0 4px 12px rgba(22, 93, 255, 0.4);
}

.mode-btn:hover:not(.active) {
    background: rgba(22, 93, 255, 0.2);
    color: var(--text-white);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.icon-btn {
    width: 40px;
    height: 40px;
    border: none;
    background: rgba(22, 93, 255, 0.1);
    color: var(--text-gray);
    cursor: pointer;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.icon-btn:hover {
    background: rgba(22, 93, 255, 0.25);
    color: var(--text-white);
}

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

/* ========================
   主内容区
   ======================== */
.content {
    position: fixed;
    top: 100px;
    left: 0;
    right: 0;
    bottom: 0;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--spacing-md);
}

.content::-webkit-scrollbar {
    width: 0;
}

/* ========================
   单列模式 - 卡片居中
   ======================== */
.single-mode {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
    padding-bottom: 100px;
}

.cards-container {
    width: 100%;
    max-width: var(--card-max-width);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* 卡片基础样式 */
.news-card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid rgba(22, 93, 255, 0.15);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    position: relative;
}

.news-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
    box-shadow: 0 12px 40px rgba(22, 93, 255, 0.25);
}

/* 突发卡片 */
.news-card.urgent {
    border-color: var(--accent-red);
    animation: urgentBorder 2s ease-in-out infinite;
}

@keyframes urgentBorder {
    0%, 100% { box-shadow: 0 0 0 2px rgba(255, 48, 0, 0.3); }
    50% { box-shadow: 0 0 0 4px rgba(255, 48, 0, 0.5); }
}

/* 海报区域 */
.card-poster {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 10;
    overflow: hidden;
    background: linear-gradient(135deg, #1A2B4A 0%, #0D1832 100%);
}

.card-poster img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.news-card:hover .card-poster img {
    transform: scale(1.05);
}

/* 标签 */
.poster-tag {
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    z-index: 10;
    backdrop-filter: blur(8px);
}

.poster-tag.urgent {
    background: linear-gradient(135deg, var(--accent-red) 0%, #FF6B6B 100%);
    color: #FFFFFF;
    box-shadow: 0 4px 12px rgba(255, 48, 0, 0.4);
}

.poster-tag.normal {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: #FFFFFF;
    box-shadow: 0 4px 12px rgba(22, 93, 255, 0.4);
}

/* 卡片内容 */
.card-content {
    padding: var(--spacing-md);
}

.card-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: var(--spacing-xs);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-summary {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 元信息 */
.card-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.meta-item {
    font-size: 12px;
    color: var(--text-gray);
    display: flex;
    align-items: center;
    gap: 4px;
}

.meta-item.hot {
    color: var(--accent-orange);
    font-weight: 500;
}

/* ========================
   双列模式 - 瀑布流
   ======================== */
.double-mode {
    width: 100%;
}

.waterfall {
    column-count: 2;
    column-gap: var(--spacing-sm);
    width: 100%;
}

.double-card {
    break-inside: avoid;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-sm);
    overflow: hidden;
    border: 1px solid rgba(22, 93, 255, 0.15);
    transition: all 0.3s ease;
    cursor: pointer;
}

.double-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(22, 93, 255, 0.2);
}

.double-card.urgent {
    border-color: var(--accent-red);
}

.double-card-image {
    position: relative;
    width: 100%;
    aspect-ratio: 1;
    overflow: hidden;
    background: linear-gradient(135deg, #1A2B4A 0%, #0D1832 100%);
}

.double-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.double-card-tag {
    position: absolute;
    top: 8px;
    left: 8px;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
    z-index: 10;
}

.double-card-tag.urgent {
    background: var(--accent-red);
    color: #FFFFFF;
}

.double-card-tag.normal {
    background: var(--primary-color);
    color: #FFFFFF;
}

.double-card-content {
    padding: var(--spacing-sm);
}

.double-card-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-white);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 6px;
}

.double-card-source {
    font-size: 12px;
    color: var(--text-gray);
}

/* ========================
   加载指示器
   ======================== */
.loading-indicator {
    display: none;
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 12px 24px;
    background: rgba(22, 93, 255, 0.9);
    border-radius: 30px;
    z-index: 100;
}

.loading-indicator.show {
    display: flex;
    align-items: center;
    gap: 8px;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: #FFFFFF;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ========================
   响应式适配
   ======================== */
@media (max-width: 480px) {
    :root {
        --card-max-width: 100%;
        --spacing-md: 12px;
        --spacing-lg: 16px;
    }
    
    .nav-header {
        padding: 0 var(--spacing-md);
    }
    
    .logo-text {
        font-size: 18px;
    }
    
    .content {
        padding: var(--spacing-sm);
        top: 92px;
    }
    
    .card-title {
        font-size: 16px;
    }
    
    .card-summary {
        font-size: 13px;
    }
    
    .waterfall {
        column-count: 2;
    }
}