/* ═══════════════════════════════════════════════════════════
   AI Insight Daily — Fluid Glass Style
   米白底 + 深灰文字 + 毛玻璃质感 + 极简留白
   ═══════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;

  /* fluid.glass 色板 */
  --cream: #f3f0ec;
  --taupe: #d4cec6;
  --charcoal: #0b1012;
  --grey: #212325;
  --white: #ffffff;

  /* 语义色 — fallback + color-mix */
  --bg: var(--cream);
  --bg-glass: linear-gradient(180deg, rgba(255,255,255,0.45), rgba(255,255,255,0.25));
  --bg-glass-solid: rgba(255, 255, 255, 0.5);
  --text-1: var(--grey);
  --text-2: rgba(33, 35, 37, 0.6);
  --text-3: rgba(33, 35, 37, 0.35);
  --border: rgba(33, 35, 37, 0.12);
  --border-hover: rgba(33, 35, 37, 0.3);
  --blur: 2rem;
  --radius: 1.25rem;
  --radius-sm: 0.75rem;
  --radius-pill: 100px;
}

[data-theme="dark"] {
  --bg: var(--charcoal);
  --bg-glass: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.03));
  --bg-glass-solid: rgba(255, 255, 255, 0.04);
  --text-1: var(--cream);
  --text-2: rgba(243, 240, 236, 0.55);
  --text-3: rgba(243, 240, 236, 0.3);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.18);
}

/* ── Reset ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-1);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  transition: background 0.4s ease, color 0.4s ease;
}

/* 极淡噪点纹理 — SVG 内联 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.35;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

/* 极淡网格纹理叠加 */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.04;
  background-image:
    linear-gradient(rgba(33,35,37,0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(33,35,37,0.3) 1px, transparent 1px);
  background-size: 64px 64px;
}

[data-theme="dark"] body::after {
  opacity: 0.03;
  background-image:
    linear-gradient(rgba(255,255,255,0.15) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.15) 1px, transparent 1px);
}

/* ── Navbar — 毛玻璃 ── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  backdrop-filter: blur(var(--blur)) saturate(180%);
  -webkit-backdrop-filter: blur(var(--blur)) saturate(180%);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text-1);
}

.nav-logo { font-size: 1.1rem; }

.nav-title {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

/* ── Search ── */
.search-box { position: relative; }

.search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-3);
  pointer-events: none;
}

#searchInput {
  width: 13rem;
  padding: 0.5rem 0.75rem 0.5rem 2.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-glass-solid);
  backdrop-filter: blur(1rem);
  -webkit-backdrop-filter: blur(1rem);
  color: var(--text-1);
  font-size: 0.8rem;
  font-family: var(--font);
  letter-spacing: 0.02em;
  outline: none;
  transition: border-color 0.3s, width 0.3s ease;
}

#searchInput:focus {
  border-color: var(--border-hover);
  width: 16rem;
}

#searchInput::placeholder { color: var(--text-3); }

/* ── Theme Toggle ── */
.theme-toggle {
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-glass-solid);
  backdrop-filter: blur(1rem);
  -webkit-backdrop-filter: blur(1rem);
  color: var(--text-2);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: border-color 0.3s, color 0.3s;
}

.theme-toggle:hover {
  border-color: var(--border-hover);
  color: var(--text-1);
}

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

/* ── Container ── */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 5rem 2rem 3rem;
  position: relative;
  z-index: 1;
}

/* ── Hero ── */
.hero {
  text-align: center;
  padding: 5rem 0 3.5rem;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  padding: 0.3rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-2);
  margin-bottom: 1.8rem;
  background: var(--bg-glass-solid);
  backdrop-filter: blur(1rem);
  -webkit-backdrop-filter: blur(1rem);
}

.hero-title {
  font-size: 4.2rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  background: linear-gradient(180deg, var(--text-1) 0%, var(--taupe) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="light"] .hero-title {
  background: linear-gradient(180deg, #212325 0%, #a09a92 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-accent {
  /* 继承父级渐变 */
}

.hero-subtitle {
  margin-top: 1.2rem;
  font-size: 1rem;
  color: var(--text-3);
  font-weight: 400;
  letter-spacing: 0.06em;
}

/* ── Stats — 紧凑横排 ── */
.stats-row {
  display: flex;
  gap: 0;
  margin-bottom: 2.5rem;
  background: var(--bg-glass);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
  z-index: 1;
}

.stat-card {
  flex: 1;
  padding: 1.5rem 1rem;
  text-align: center;
  border-right: 1px solid var(--border);
  transition: background 0.3s;
  background: none;
  border-radius: 0;
}

.stat-card:last-child { border-right: none; }

.stat-card:hover {
  background: var(--bg-glass-solid);
}

.stat-icon {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  display: block;
  /* 去掉盒子样式 */
  width: auto;
  height: auto;
  border-radius: 0;
  background: none;
  border: none;
}

.stat-info { min-width: 0; }

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-1);
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.stat-label {
  font-size: 0.65rem;
  color: var(--text-3);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 0.4rem;
}

/* ── Filter ── */
.filter-bar {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.tag-btn {
  padding: 0.4rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-size: 0.72rem;
  font-weight: 500;
  font-family: var(--font);
  letter-spacing: 0.04em;
  cursor: pointer;
  background: transparent;
  color: var(--text-3);
  transition: border-color 0.3s, color 0.3s, background 0.3s;
  white-space: nowrap;
}

.tag-btn:hover {
  border-color: var(--border-hover);
  color: var(--text-2);
}

.tag-btn.active {
  background: var(--text-1);
  color: var(--bg);
  border-color: var(--text-1);
}

/* ── Card Grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(22rem, 1fr));
  gap: 1rem;
}

/* ── Article Card — 毛玻璃 ── */
.article-card {
  background: var(--bg-glass);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.article-card:hover {
  border-color: var(--border-hover);
}

[data-theme="light"] .article-card:hover {
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.04);
}

.card-tags {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.card-tag {
  font-size: 0.6rem;
  font-weight: 600;
  padding: 0.2rem 0.5rem;
  border-radius: 0.3rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* 柔和的标签色 */
.card-tag[data-color="blue"]   { background: rgba(100,120,180,0.1);  color: #6880b4; }
.card-tag[data-color="purple"] { background: rgba(140,110,170,0.1);  color: #8c6eaa; }
.card-tag[data-color="orange"] { background: rgba(180,140,80,0.1);   color: #a08050; }
.card-tag[data-color="green"]  { background: rgba(80,150,100,0.1);   color: #509664; }
.card-tag[data-color="red"]    { background: rgba(180,90,90,0.1);    color: #b45a5a; }
.card-tag[data-color="gray"]   { background: rgba(130,130,130,0.08); color: #8a8a8a; }

[data-theme="dark"] .card-tag[data-color="blue"]   { background: rgba(130,160,220,0.12); color: #8aa0dc; }
[data-theme="dark"] .card-tag[data-color="purple"] { background: rgba(170,140,210,0.12); color: #aa8cd2; }
[data-theme="dark"] .card-tag[data-color="orange"] { background: rgba(220,180,110,0.12); color: #dcb46e; }
[data-theme="dark"] .card-tag[data-color="green"]  { background: rgba(100,190,130,0.12); color: #64be82; }
[data-theme="dark"] .card-tag[data-color="red"]    { background: rgba(220,120,120,0.12); color: #dc7878; }
[data-theme="dark"] .card-tag[data-color="gray"]   { background: rgba(160,160,160,0.1);  color: #a0a0a0; }

.card-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: -0.01em;
  color: var(--text-1);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-summary {
  font-size: 0.82rem;
  color: var(--text-2);
  line-height: 1.7;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border);
}

.card-author {
  font-size: 0.72rem;
  color: var(--text-2);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.card-date {
  font-size: 0.68rem;
  color: var(--text-3);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.03em;
}

/* ── Empty ── */
.empty-state {
  text-align: center;
  padding: 5rem 1.5rem;
  color: var(--text-3);
}
.empty-icon { font-size: 3rem; margin-bottom: 1rem; }

/* ── Modal — 毛玻璃 ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(11, 16, 18, 0.5);
  backdrop-filter: blur(1.5rem);
  -webkit-backdrop-filter: blur(1.5rem);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal {
  background: var(--bg-glass);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 42rem;
  width: 100%;
  max-height: 84vh;
  overflow-y: auto;
  padding: 2.5rem;
  position: relative;
}

[data-theme="light"] .modal {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(2.5rem) saturate(180%);
  -webkit-backdrop-filter: blur(2.5rem) saturate(180%);
}

[data-theme="dark"] .modal {
  background: rgba(33, 35, 37, 0.85);
  backdrop-filter: blur(2.5rem) saturate(150%);
  -webkit-backdrop-filter: blur(2.5rem) saturate(150%);
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--bg-glass-solid);
  color: var(--text-3);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: border-color 0.3s, color 0.3s;
}

.modal-close:hover {
  border-color: var(--border-hover);
  color: var(--text-1);
}

.modal-tags { display: flex; gap: 0.35rem; margin-bottom: 1rem; }

.modal-title {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.35;
  margin-bottom: 0.6rem;
  color: var(--text-1);
}

.modal-meta {
  font-size: 0.78rem;
  color: var(--text-3);
  display: flex;
  gap: 1rem;
  letter-spacing: 0.02em;
}

.modal-meta a {
  color: var(--text-2);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color 0.2s;
}
.modal-meta a:hover { color: var(--text-1); }

.modal-divider {
  height: 1px;
  background: var(--border);
  margin: 1.5rem 0;
}

.modal-body {
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--text-2);
  word-break: break-word;
}

.modal-body p { margin-bottom: 1rem; }

/* ── Footer ── */
.footer {
  text-align: center;
  padding: 2.5rem 2rem;
  font-size: 0.72rem;
  color: var(--text-3);
  border-top: 1px solid var(--border);
  margin-top: 4rem;
  letter-spacing: 0.06em;
  position: relative;
  z-index: 1;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .stats-row { flex-wrap: wrap; }
  .stat-card { flex: 1 1 45%; border-right: none; border-bottom: 1px solid var(--border); }
  .stat-card:nth-child(odd) { border-right: 1px solid var(--border); }
  .stat-card:nth-last-child(-n+2) { border-bottom: none; }
  .card-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 2.6rem; }
  #searchInput { width: 10rem; }
  #searchInput:focus { width: 12rem; }
  .modal { padding: 1.8rem; }
  .container { padding: 4.5rem 1.5rem 2.5rem; }
}

@media (max-width: 480px) {
  .nav-title { font-size: 0.7rem; }
  .stat-card { padding: 1rem 0.8rem; gap: 0.7rem; }
  .stat-icon { width: 2.2rem; height: 2.2rem; font-size: 1rem; }
  .stat-number { font-size: 1.2rem; }
  .hero { padding: 2.5rem 0 2rem; }
  .hero-title { font-size: 1.7rem; }
}

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--taupe); border-radius: 2px; }

::selection { background: rgba(212, 206, 198, 0.3); }