/* ================================================================
   TechPulse — 科技新闻聚合网站样式
   ================================================================ */

:root {
    /* 深色主题（默认） */
    --bg-primary: #0a0e14;
    --bg-secondary: #12161e;
    --bg-card: #181c26;
    --bg-card-hover: #1e2330;
    --border: #252a36;
    --text-primary: #e6e8ec;
    --text-secondary: #8b92a0;
    --text-muted: #5c6370;
    --accent: #39bae6;
    --accent-glow: rgba(57, 186, 230, 0.15);
    --shadow: rgba(0, 0, 0, 0.3);
    --category-ai: #ff6b8a;
    --category-gpu: #7dcfff;
    --category-cpu: #ffb454;
    --category-foundry: #a37acc;
    --category-semiconductor: #4fd2b2;
    --category-digital: #ff8f40;
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.2s ease;
}

/* 浅色主题 */
[data-theme="light"] {
    --bg-primary: #f5f6f8;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f0f2f5;
    --border: #e2e5ea;
    --text-primary: #1a1d24;
    --text-secondary: #5a6070;
    --text-muted: #949aa8;
    --accent: #1a8fbf;
    --accent-glow: rgba(26, 143, 191, 0.1);
    --shadow: rgba(0, 0, 0, 0.08);
}

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

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background 0.35s ease, color 0.35s ease;
}

/* ── Header ──────────────────────────────────────── */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: color-mix(in srgb, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 0 24px;
}
.header-inner {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
    gap: 24px;
}
.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
    flex-shrink: 0;
}
.logo-icon { font-size: 1.4rem; }
.logo-text {
    background: linear-gradient(135deg, var(--accent), #7dcfff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* ── 主题切换按钮 ────────────────────────────────── */
.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    flex-shrink: 0;
    margin-left: auto;
}
.theme-toggle:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-glow);
}
.nav {
    display: flex;
    gap: 4px;
    overflow-x: auto;
    -ms-overflow-style: none;
    scrollbar-width: none;
}
.nav::-webkit-scrollbar { display: none; }
.nav-item {
    background: none;
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.875rem;
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--transition);
    font-family: inherit;
}
.nav-item:hover {
    color: var(--text-primary);
    background: var(--bg-secondary);
}
.nav-item.active {
    color: var(--accent);
    background: var(--accent-glow);
    border-color: rgba(57, 186, 230, 0.3);
}

/* ── Main ────────────────────────────────────────── */
.main {
    max-width: 1280px;
    margin: 0 auto;
    padding: 32px 24px 64px;
}

/* ── Loading ─────────────────────────────────────── */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 80px 0;
    color: var(--text-muted);
    gap: 16px;
}
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.error, .empty {
    text-align: center;
    padding: 80px 0;
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* ── News Grid ───────────────────────────────────── */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 20px;
}

.news-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.news-card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(57, 186, 230, 0.3);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--shadow);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}
.card-category {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.cat-AI              { background: rgba(255,107,138,0.15); color: var(--category-ai); }
.cat-GPU             { background: rgba(125,207,255,0.15); color: var(--category-gpu); }
.cat-CPU             { background: rgba(255,180,84,0.15);  color: var(--category-cpu); }
.cat-Foundry         { background: rgba(163,122,204,0.15); color: var(--category-foundry); }
.cat-Semiconductor   { background: rgba(79,210,178,0.15);  color: var(--category-semiconductor); }
.cat-Digital         { background: rgba(255,143,64,0.15);  color: var(--category-digital); }

.card-time {
    font-size: 0.8rem;
    color: var(--text-muted);
}
.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.4;
    color: var(--text-primary);
}
.card-summary {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
    flex: 1;
}
.card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-muted);
    padding-top: 8px;
    border-top: 1px solid var(--border);
}
.card-source {
    display: flex;
    align-items: center;
    gap: 6px;
}
.card-source-avatar {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-glow);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
}

/* ── Pagination ──────────────────────────────────── */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 32px 0;
}
.pagination button {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 20px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    transition: all var(--transition);
}
.pagination button:hover:not(:disabled) {
    background: var(--accent-glow);
    border-color: var(--accent);
}
.pagination button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}
#pageInfo {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ── Modal ───────────────────────────────────────── */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    z-index: 200;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.modal-overlay.active { display: flex; }
.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    max-width: 640px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
}
.modal-close {
    position: absolute;
    top: 12px;
    right: 16px;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
}
.modal-close:hover { color: var(--text-primary); }
.modal-content { padding: 32px; }

.modal-category { margin-bottom: 12px; }
.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    line-height: 1.4;
}
.modal-summary {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.7;
}
.modal-keypoints {
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    padding: 20px;
    margin-bottom: 24px;
}
.modal-keypoints h3 {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
}
.modal-keypoints ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.modal-keypoints li {
    font-size: 0.95rem;
    color: var(--text-primary);
    padding-left: 16px;
    position: relative;
}
.modal-keypoints li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
}
.modal-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--text-muted);
}
.modal-source-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--accent);
    text-decoration: none;
    padding: 6px 14px;
    border: 1px solid rgba(57, 186, 230, 0.3);
    border-radius: 20px;
    transition: all var(--transition);
}
.modal-source-link:hover {
    background: var(--accent-glow);
}

/* ── Footer ──────────────────────────────────────── */
.footer {
    text-align: center;
    padding: 32px 24px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ── Responsive ──────────────────────────────────── */
@media (max-width: 768px) {
    .header-inner {
        flex-wrap: wrap;
        height: auto;
        padding: 12px 0;
        gap: 8px;
    }
    .theme-toggle {
        order: 1;
        margin-left: 0;
    }
    .logo {
        order: 0;
    }
    .nav {
        order: 2;
        width: 100%;
    }
    .news-grid {
        grid-template-columns: 1fr;
    }
    .main {
        padding: 20px 16px 48px;
    }
    .modal-content { padding: 24px; }
    .modal-title { font-size: 1.25rem; }
}