/* ── Reset & Variables ─────────────────────────── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* ── Light Theme ──────────────────────────────── */
[data-theme="light"] {
    --bg-primary: #faf9f7;
    --bg-card: #ffffff;
    --bg-tag: #f0eeeb;
    --bg-hover: #f5f3f0;
    --text-primary: #1a1a1a;
    --text-secondary: #6b6b6b;
    --text-muted: #999999;
    --border: #e8e6e3;
    --accent: #d4a574;
    --accent-hover: #c4955f;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.1);
    --tab-bg: #faf9f7;
}

/* ── Dark Theme ───────────────────────────────── */
[data-theme="dark"] {
    --bg-primary: #1a1a2e;
    --bg-card: #222240;
    --bg-tag: #2a2a4a;
    --bg-hover: #282848;
    --text-primary: #e8e6e3;
    --text-secondary: #a0a0b0;
    --text-muted: #6b6b80;
    --border: #333355;
    --accent: #7c6fe0;
    --accent-hover: #6b5fd0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
    --tab-bg: #1a1a2e;
}

/* ── Base ──────────────────────────────────────── */
html, body {
    height: 100%;
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* ── Sticky Top (Header + Tabs) ───────────────── */
.sticky-top {
    flex-shrink: 0;
    background: var(--bg-primary);
    z-index: 20;
    border-bottom: 1px solid var(--border);
    transition: background 0.3s;
}

/* ── Header ───────────────────────────────────── */
.header {
    border-bottom: 1px solid var(--border);
}

.header-inner {
    max-width: 680px;
    margin: 0 auto;
    padding: 16px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.theme-toggle {
    background: var(--bg-tag);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 6px 12px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s;
}

.theme-toggle:hover {
    border-color: var(--accent);
}

[data-theme="light"] .icon-dark { display: none; }
[data-theme="dark"] .icon-light { display: none; }

/* ── Tabs ─────────────────────────────────────── */
.tabs {
    background: var(--tab-bg);
}

.tabs-inner {
    max-width: 680px;
    margin: 0 auto;
    display: flex;
    padding: 0 16px;
}

.tab {
    flex: 1;
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    padding: 12px 0;
    transition: all 0.2s;
    text-align: center;
}

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

.tab.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
    font-weight: 600;
}

/* ── Scrollable Content ───────────────────────── */
.content {
    flex: 1;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

.container {
    max-width: 680px;
    margin: 0 auto;
    padding: 20px 16px 0;
}

/* ── Tab Panels ───────────────────────────────── */
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ── News Card ────────────────────────────────── */
.news-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 12px;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}

.news-card:hover {
    box-shadow: var(--shadow-hover);
    border-color: var(--accent);
}

.news-card .card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 8px;
}

.news-card .card-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.4;
}

.news-card .card-date {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
    flex-shrink: 0;
}

.news-card .card-summary {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-card .card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 10px;
}

.card-reason, .modal-reason {
    font-size: 0.82rem;
    color: var(--accent);
    margin-top: 8px;
    line-height: 1.5;
}

.card-sources, .modal-sources {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 8px;
}

.card-sources a, .modal-sources a {
    color: var(--accent);
    text-decoration: none;
}

.card-sources a:hover, .modal-sources a:hover {
    text-decoration: underline;
}

.tag {
    background: var(--bg-tag);
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 10px;
}

.tag.level-phenomenal {
    background: var(--accent);
    color: #fff;
}

/* ── Archive Tree ─────────────────────────────── */
.archive-tree {
    padding-bottom: 16px;
}

.tree-node {
    margin-bottom: 2px;
}

.tree-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    background: none;
    border: none;
    padding: 10px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.92rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: background 0.15s;
    text-align: left;
    font-family: var(--font-sans);
}

.tree-toggle:hover {
    background: var(--bg-hover);
}

.tree-toggle .arrow {
    display: inline-block;
    font-size: 0.65rem;
    transition: transform 0.2s;
    color: var(--text-muted);
    width: 10px;
    flex-shrink: 0;
}

.tree-node.open > .tree-toggle .arrow {
    transform: rotate(90deg);
}

.tree-toggle .node-label {
    flex: 1;
}

.tree-toggle .node-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 400;
}

.tree-children {
    display: none;
    padding-left: 20px;
}

.tree-node.open > .tree-children {
    display: block;
}

/* Day-level news items */
.tree-news-list {
    display: none;
    padding-left: 20px;
}

.tree-node.open > .tree-news-list {
    display: block;
}

.tree-news-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 9px 14px;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.15s;
    font-size: 0.88rem;
    gap: 12px;
}

.tree-news-item:hover {
    background: var(--bg-hover);
}

.tree-news-item .item-title {
    color: var(--text-primary);
    font-weight: 400;
    line-height: 1.4;
}

.tree-news-item .item-level {
    font-size: 0.72rem;
    color: var(--text-muted);
    flex-shrink: 0;
    white-space: nowrap;
}

.tree-news-item .item-level.phenomenal {
    color: var(--accent);
    font-weight: 500;
}

/* ── Empty State ──────────────────────────────── */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ── Modal ─────────────────────────────────────── */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 100;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

.modal-overlay.active { display: flex; }

.modal {
    background: var(--bg-card);
    border-radius: 16px;
    max-width: 600px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    padding: 24px;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.modal-close {
    position: absolute;
    top: 12px;
    right: 16px;
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
}

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

.modal-content h2 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.modal-content .meta {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.modal-content .body {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ── Footer ───────────────────────────────────── */
.footer {
    text-align: center;
    padding: 24px 0;
    color: var(--text-muted);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    margin-top: 32px;
}

.footer .update-schedule {
    margin-top: 6px;
    font-size: 0.75rem;
    opacity: 0.8;
}

/* ── Responsive ───────────────────────────────── */
@media (max-width: 480px) {
    .header-inner, .container { padding-left: 12px; padding-right: 12px; }
    .tabs-inner { padding: 0 12px; }
    .logo { font-size: 1.1rem; }
    .news-card { padding: 14px; }
    .tab { font-size: 0.84rem; }
}