:root {
  --blue-500: #2a98ff;
  --blue-brand: #2d99ff;
  --blue-700: #148af8;
  --blue-100: rgba(54, 158, 255, 0.1);
  --ink: rgba(0, 0, 0, 0.7);
  --muted: rgba(0, 0, 0, 0.5);
  --soft-muted: #5f6368;
  --white: #ffffff;
  --line: rgba(0, 0, 0, 0.1);
  --radius-card: 20px;
  --radius-pill: 999px;
  --space-1: 8px;
  --space-2: 12px;
  --space-3: 16px;
  --space-4: 24px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: #f8f9fa;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.5;
}
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--white);
}
.header-inner, .filter-inner, .feed { width: min(780px, calc(100% - 40px)); margin: 0 auto; }
.header-inner { height: 80px; display: flex; align-items: center; justify-content: space-between; gap: var(--space-4); padding-top: 16px; }
.brand { display: inline-flex; align-items: center; gap: var(--space-1); color: var(--blue-brand); text-decoration: none; }
.brand-logo { display: block; width: 35px; height: 35px; flex: 0 0 35px; }
.brand-name { display: block; width: auto; height: 20px; }
.top-actions { display: flex; align-items: center; gap: 20px; }
.settings-button:active, .tab:active, .source-link:active { transform: translateY(1px); }
.settings-button { display: grid; place-items: center; width: 40px; height: 40px; padding: 0; border: 0; border-radius: 50%; background: transparent; cursor: pointer; }
.settings-button img { display: block; width: 24px; height: 24px; }
.filter-inner { min-height: 55px; display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.tabs { display: flex; align-items: center; gap: var(--space-4); overflow-x: auto; scrollbar-width: none; }
.tabs::-webkit-scrollbar { display: none; }
.tab { min-height: 51px; padding: 8px 16px; border: 0; border-radius: var(--radius-pill); color: var(--soft-muted); background: transparent; white-space: nowrap; cursor: pointer; font-size: 15px; font-weight: 400; }
.tab.is-active { min-height: 36px; color: var(--white); background: var(--blue-500); font-weight: 650; }
.search-field { display: flex; align-items: center; gap: var(--space-2); width: 280px; height: 40px; padding: 0 var(--space-3); border-radius: 20px; color: var(--muted); background: rgba(0, 0, 0, 0.03); }
.search-icon { display: block; width: 18px; height: 18px; flex: 0 0 18px; }
.search-field input { width: 100%; min-width: 0; border: 0; outline: 0; color: var(--ink); background: transparent; font-size: 14px; }
.search-field input::placeholder { color: rgba(0, 0, 0, 0.4); }

.feed { width: 100%; max-width: none; min-height: 889px; padding: 24px 20px 64px; background: var(--blue-100); }
.cards { width: min(780px, 100%); margin: 0 auto; display: grid; gap: var(--space-3); }
.card { display: grid; grid-template-columns: minmax(0, 1fr) 140px; align-items: start; gap: var(--space-4); min-height: 192px; padding: var(--space-4); border: 0; border-radius: var(--radius-card); background: var(--white); box-shadow: none; }
.card.no-image { grid-template-columns: 1fr; min-height: 0; }
.card-content { min-width: 0; min-height: 0; display: flex; flex-direction: column; gap: var(--space-2); color: inherit; text-decoration: none; }
.card-content:active { opacity: 0.72; }
.meta { display: flex; align-items: center; gap: var(--space-2); margin-top: 0; padding-top: var(--space-1); color: var(--soft-muted); font-size: 12px; }
.source { display: inline-flex; align-items: center; gap: 4px; color: var(--blue-700); font-weight: 400; }
.source-icon { display: block; width: 14px; height: auto; }
.dot { color: var(--soft-muted); }
.time { font-weight: 350; }
.card h2 { margin: 0; color: var(--ink); font-size: 18px; font-weight: 550; line-height: 1.4; letter-spacing: 0; }
.summary { display: -webkit-box; margin: 0; overflow: hidden; color: var(--muted); font-size: 14px; line-height: 1.5; -webkit-box-orient: vertical; -webkit-line-clamp: 2; }
.card-media { position: relative; align-self: start; width: 140px; height: 144px; overflow: hidden; border-radius: 8px; background: var(--blue-100); }
.card-media img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.media-label { display: none; }
.empty-state { padding: 48px 0; color: var(--muted); text-align: center; }

@media (max-width: 680px) {
  .header-inner, .filter-inner { width: min(100% - 28px, 560px); }
  .header-inner { height: 68px; padding-top: 8px; }
  .brand-name { display: none; }
  .filter-inner { min-height: 52px; }
  .top-actions { gap: var(--space-1); flex: 1; justify-content: flex-end; }
  .search-field { width: min(280px, calc(100vw - 112px)); }
  .feed { padding: 16px 14px 40px; }
  .card { grid-template-columns: minmax(0, 1fr) 112px; gap: 12px; min-height: 160px; padding: 16px; }
  .card-media { width: 112px; height: 116px; }
  .card h2 { font-size: 16px; }
}