/* ============================================================
   CSS Custom Properties (theming)
   ============================================================ */
:root {
  /* Light theme (default) */
  --bg: #f8f9fa;
  --bg-card: #ffffff;
  --bg-header: #ffffff;
  --bg-footer: #f1f3f5;
  --text-primary: #1a1a2e;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-hover: 0 4px 12px rgba(0,0,0,.12), 0 2px 4px rgba(0,0,0,.08);
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --cat-tab-active-bg: #3b82f6;
  --cat-tab-active-text: #ffffff;
  --cat-tab-bg: #f3f4f6;
  --cat-tab-text: #374151;
  --cat-tab-hover: #e5e7eb;
  --skeleton-from: #e5e7eb;
  --skeleton-to: #f3f4f6;
  --badge-tech: #3b82f6;
  --badge-sports: #10b981;
  --badge-business: #f59e0b;
  --badge-science: #8b5cf6;
  --badge-politics: #ef4444;
  --badge-vietnam: #06b6d4;
  --badge-default: #6b7280;
}

[data-theme="dark"] {
  --bg: #0f1117;
  --bg-card: #1a1d27;
  --bg-header: #13151f;
  --bg-footer: #0d0f18;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #2a2d3e;
  --shadow: 0 1px 3px rgba(0,0,0,.4), 0 1px 2px rgba(0,0,0,.3);
  --shadow-hover: 0 4px 16px rgba(0,0,0,.5), 0 2px 6px rgba(0,0,0,.4);
  --accent: #60a5fa;
  --accent-hover: #93c5fd;
  --cat-tab-active-bg: #3b82f6;
  --cat-tab-active-text: #ffffff;
  --cat-tab-bg: #1e2130;
  --cat-tab-text: #cbd5e1;
  --cat-tab-hover: #252840;
  --skeleton-from: #1e2130;
  --skeleton-to: #252840;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue',
               Arial, 'Noto Sans', sans-serif;
  background-color: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color .25s ease, color .25s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

button {
  cursor: pointer;
  font-family: inherit;
}

img { max-width: 100%; }

/* ============================================================
   Header
   ============================================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-header);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: background-color .25s ease, border-color .25s ease;
}

.header-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: .75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: .5rem;
  text-decoration: none;
  color: var(--text-primary);
}

.logo-icon { font-size: 1.5rem; }

.logo-text {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -.02em;
}

.header-actions { display: flex; align-items: center; gap: .5rem; }

/* Theme toggle */
.icon-btn {
  background: var(--cat-tab-bg);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: background .2s, border-color .2s, transform .1s;
}
.icon-btn:hover { background: var(--cat-tab-hover); transform: scale(1.05); }
.icon-btn:active { transform: scale(.95); }

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

/* Category tabs */
.categories {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: .375rem;
  padding: .5rem 1.25rem .75rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.categories::-webkit-scrollbar { display: none; }

.cat-btn {
  flex-shrink: 0;
  padding: .375rem .875rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-size: .85rem;
  font-weight: 500;
  background: var(--cat-tab-bg);
  color: var(--cat-tab-text);
  transition: background .18s, color .18s, border-color .18s, transform .1s;
  white-space: nowrap;
}
.cat-btn:hover { background: var(--cat-tab-hover); }
.cat-btn:active { transform: scale(.96); }
.cat-btn.active {
  background: var(--cat-tab-active-bg);
  color: var(--cat-tab-active-text);
  border-color: var(--cat-tab-active-bg);
}

/* ============================================================
   Main (Centered Editorial Stream like newsdigest)
   ============================================================ */
.main {
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3.5rem;
  flex: 1;
}

/* Stats bar */
.stats-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1.25rem;
  font-size: .82rem;
  color: var(--text-muted);
}
.stats-text { font-weight: 500; }
.last-updated { font-style: italic; }

/* ============================================================
   News Stream (Horizontal Row Cards)
   ============================================================ */
.news-grid {
  display: flex;
  flex-direction: column;
  gap: 1.35rem;
  width: 100%;
}

/* ============================================================
   News Card (Khung Ngang)
   ============================================================ */
.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.35rem 1.5rem 1.15rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: .75rem;
  transition: all .2s cubic-bezier(0.16, 1, 0.3, 1);
  animation: fadeInUp .3s ease both;
  width: 100%;
}
.news-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
  border-color: var(--accent);
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Card header row: source + category + time */
.card-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .65rem;
  flex-wrap: wrap;
}

.card-badges {
  display: flex;
  align-items: center;
  gap: .45rem;
  flex-wrap: wrap;
}

.source-badge {
  display: inline-flex;
  align-items: center;
  gap: .3rem;
  padding: .2rem .65rem;
  border-radius: 999px;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: #fff;
  white-space: nowrap;
}

.category-pill {
  display: inline-flex;
  align-items: center;
  padding: .18rem .55rem;
  border-radius: 999px;
  font-size: .72rem;
  font-weight: 600;
  background: var(--cat-tab-bg);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

/* Category badge colors */
.badge-tech     { background: var(--badge-tech); }
.badge-sports   { background: var(--badge-sports); }
.badge-business { background: var(--badge-business); }
.badge-science  { background: var(--badge-science); }
.badge-politics { background: var(--badge-politics); }
.badge-vietnam  { background: var(--badge-vietnam); }
.badge-default  { background: var(--badge-default); }

.card-time {
  font-size: .78rem;
  color: var(--text-muted);
  white-space: nowrap;
}

/* Card title */
.card-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text-primary);
  margin: 0.15rem 0 0.25rem;
}
.card-title a {
  color: inherit;
  text-decoration: none;
  transition: color .15s ease;
}
.card-title a:hover { color: var(--accent); }

/* AI Summary Box - Khung Ngang Tóm Tắt Nổi Bật */
.ai-summary-box {
  background: color-mix(in srgb, var(--accent) 6%, var(--bg));
  border-left: 3.5px solid var(--accent);
  border-top: 1px solid color-mix(in srgb, var(--accent) 15%, var(--border));
  border-right: 1px solid color-mix(in srgb, var(--accent) 15%, var(--border));
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 15%, var(--border));
  border-radius: 0 10px 10px 0;
  padding: .85rem 1.15rem;
  margin: .25rem 0 .4rem;
  display: flex;
  flex-direction: column;
  gap: .45rem;
}

.ai-summary-header {
  display: flex;
  align-items: center;
  gap: .35rem;
}

.ai-badge {
  font-size: .72rem;
  font-weight: 750;
  letter-spacing: .5px;
  color: var(--accent);
  text-transform: uppercase;
}

.ai-sparkle {
  font-size: .85rem;
}

/* Card summary */
.card-summary {
  font-size: .925rem;
  color: var(--text-primary);
  line-height: 1.68;
  margin: 0;
}

/* Card footer row */
.card-footer-row {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-top: .4rem;
  border-top: 1px solid color-mix(in srgb, var(--border) 60%, transparent);
  margin-top: .15rem;
}

.read-original-btn {
  font-size: .825rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .3rem .65rem;
  border-radius: 6px;
  transition: all .15s ease;
}
.read-original-btn:hover {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
}
.external-icon {
  flex-shrink: 0;
  stroke: currentColor;
}

/* ============================================================
   Skeleton loading cards (Horizontal)
   ============================================================ */
.skeleton-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.35rem 1.5rem;
  height: 160px;
  width: 100%;
  position: relative;
  overflow: hidden;
}
.skeleton-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    color-mix(in srgb, var(--skeleton-to) 60%, transparent) 50%,
    transparent 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.4s ease-in-out infinite;
  background-color: var(--skeleton-from);
}
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position:  200% 0; }
}

/* ============================================================
   Empty & Error states
   ============================================================ */
.empty-state,
.error-state {
  text-align: center;
  padding: 4rem 1rem;
  color: var(--text-secondary);
}
.empty-icon,
.error-icon {
  display: block;
  font-size: 3rem;
  margin-bottom: 1rem;
}
.empty-sub { font-size: .875rem; color: var(--text-muted); margin-top: .5rem; }

.retry-btn {
  margin-top: 1.25rem;
  padding: .5rem 1.5rem;
  border-radius: 8px;
  border: 2px solid var(--accent);
  background: transparent;
  color: var(--accent);
  font-weight: 600;
  font-size: .875rem;
  transition: background .2s, color .2s;
}
.retry-btn:hover {
  background: var(--accent);
  color: #fff;
}

/* ============================================================
   Load more
   ============================================================ */
.load-more-wrap { text-align: center; margin-top: 2rem; }

.load-more-btn {
  padding: .625rem 2rem;
  border-radius: 8px;
  border: 2px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: .875rem;
  transition: border-color .2s, color .2s, background .2s;
}
.load-more-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-card));
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--bg-footer);
  border-top: 1px solid var(--border);
  padding: 1.5rem 1.25rem;
  text-align: center;
  font-size: .82rem;
  color: var(--text-muted);
  transition: background .25s ease;
}
.footer-inner {
  max-width: 860px;
  margin: 0 auto;
}
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--accent); }
.footer-sub { margin-top: .25rem; }

/* ============================================================
   Utility
   ============================================================ */
.hidden { display: none !important; }

/* ============================================================
   Sources Management & Modal
   ============================================================ */
.sources-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}
.sources-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 1rem;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  width: 100%;
  max-width: 640px;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 40px rgba(0,0,0,0.25);
  animation: modalIn 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalIn {
  from { opacity: 0; transform: scale(0.96) translateY(10px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
}
.modal-header h2 {
  font-size: 1.15rem;
  margin: 0;
  color: var(--text-primary);
}
.modal-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-muted);
  cursor: pointer;
  line-height: 1;
  padding: 0.2rem;
}
.modal-close:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.modal-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0.25rem 0;
}

.settings-section {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
}

.settings-section-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.settings-section-icon {
  font-size: 1.5rem;
  line-height: 1;
}

.settings-section-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.settings-section-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.ai-config-box {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.ai-locked-box {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 1rem;
  background: var(--bg-card);
  border: 1px dashed var(--border);
  border-radius: 8px;
}

.lock-icon {
  font-size: 1.5rem;
  line-height: 1;
}

.lock-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.lock-hint {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.lock-input-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.lock-input-row input {
  flex: 1;
  padding: 0.45rem 0.65rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text-primary);
  font-size: 0.85rem;
  outline: none;
}
.lock-input-row input:focus {
  border-color: var(--accent);
}

.unlocked-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.45rem 0.75rem;
  background: color-mix(in srgb, #10b981 12%, transparent);
  border: 1px solid color-mix(in srgb, #10b981 30%, transparent);
  border-radius: 6px;
  margin-bottom: 0.25rem;
}

.unlocked-text {
  font-size: 0.8rem;
  font-weight: 600;
  color: #10b981;
}

.btn-lock-toggle {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.75rem;
  cursor: pointer;
  text-decoration: underline;
}
.btn-lock-toggle:hover {
  color: #ef4444;
}

.ai-config-footer {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.25rem;
}

.source-form {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
}
.form-title {
  font-size: 0.95rem;
  margin: 0 0 1rem 0;
  color: var(--text-primary);
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}
@media (max-width: 540px) {
  .form-grid { grid-template-columns: 1fr; }
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.form-group label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
}
.form-group input, .form-group select {
  padding: 0.55rem 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: 0.85rem;
  outline: none;
}
.form-group input:focus, .form-group select:focus {
  border-color: var(--accent);
}

.form-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.55rem 1.25rem;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.85rem;
  cursor: pointer;
  transition: opacity 0.2s;
}
.btn-primary:hover { opacity: 0.9; }

.btn-secondary {
  background: var(--bg);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
}
.btn-secondary:hover { color: var(--text-primary); border-color: var(--text-muted); }

.form-status {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.sources-list-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.sources-list-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.sources-header-btns {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.sources-list-header h3 {
  font-size: 0.95rem;
  margin: 0;
  color: var(--text-primary);
}

.sources-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-height: 260px;
  overflow-y: auto;
}

.source-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  font-size: 0.85rem;
}
.source-info {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-width: 0;
}
.source-name {
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.source-tag {
  font-size: 0.7rem;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-secondary);
}
.source-tag.custom {
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  color: var(--accent);
  font-weight: 600;
}
.btn-delete-source {
  background: none;
  border: none;
  color: #ef4444;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  font-size: 0.8rem;
  border-radius: 4px;
  transition: background 0.2s;
}
.btn-delete-source:hover {
  background: rgba(239, 68, 68, 0.1);
}