:root {
  --bg: #ececec;
  --card: #ffffff;
  --text: #1a1a1a;
  --muted: #8a8a8a;
  --line: #dcdcdc;
  --accent: #1a1a1a;

  --gutter: clamp(16px, 4vw, 48px);
  --card-w: min(72vw, 960px);
  --card-gap: 12px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161616;
    --card: #222222;
    --text: #ededed;
    --muted: #8a8a8a;
    --line: #333333;
    --accent: #ededed;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  display: grid;
  grid-template-rows: auto 1fr;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.5 var(--font);
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ---------- 顶栏 ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px var(--gutter);
}

.wordmark {
  font-weight: 600;
  letter-spacing: 0.01em;
}

.topnav {
  display: flex;
  gap: 24px;
}

.topnav a {
  color: var(--muted);
  transition: color 0.15s;
}

.topnav a:hover,
.topnav a[aria-current="page"] {
  color: var(--text);
}

/* ---------- 横向卡片轨道 ---------- */

.rail {
  display: flex;
  gap: var(--card-gap);
  min-height: 0;
  padding: 8px var(--gutter) 56px;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x mandatory;
  scroll-padding-inline: var(--gutter);
  scrollbar-width: none;
}

.rail::-webkit-scrollbar {
  display: none;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  flex: 0 0 var(--card-w);
  background: var(--card);
  scroll-snap-align: start;
}

.card__meta {
  padding: 16px 20px;
  color: var(--muted);
  font-size: 12px;
}

.card__placeholder {
  display: grid;
  flex: 1;
  place-items: center;
  margin: 0 20px 20px;
  border: 1px dashed var(--line);
  color: var(--muted);
}

/* ---------- 手机 ---------- */

@media (max-width: 640px) {
  :root {
    --card-w: 84vw;
  }

  .topnav {
    gap: 16px;
  }
}