:root {
  color-scheme: light;
  --ink: #232622;
  --muted: #666d66;
  --paper: #f8f6ef;
  --paper-strong: #fffefa;
  --accent: #2f766f;
  --warm: #9b6347;
  --line: rgba(35, 38, 34, 0.12);
  --line-strong: rgba(35, 38, 34, 0.2);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--paper);
}

body {
  min-height: 100%;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}

a {
  color: var(--ink);
  font: inherit;
  font-weight: 680;
  text-decoration-color: rgba(14, 116, 113, 0.36);
  text-underline-offset: 4px;
}

a:focus-visible {
  outline: 3px solid rgba(47, 118, 111, 0.26);
  outline-offset: 3px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(820px, calc(100% - 36px));
  margin: 0 auto;
  padding: 24px 0 12px;
}

.brand,
.home-link {
  color: var(--ink);
  text-decoration: none;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.95rem;
  font-weight: 680;
}

.brand-mark {
  width: 18px;
  height: 18px;
  border: 2px solid var(--ink);
  border-right-color: var(--accent);
  border-bottom-color: var(--warm);
  transform: rotate(45deg);
}

.home-link {
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
}

.compact-shell {
  width: min(820px, calc(100% - 36px));
  margin: 0 auto;
  padding: 44px 0 72px;
}

.eyebrow,
.card-label {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 760;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 680px;
  margin-bottom: 14px;
  font-size: clamp(2.25rem, 5vw, 4rem);
  font-weight: 760;
  line-height: 1.04;
}

.definition {
  max-width: 680px;
  margin-bottom: 26px;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.75;
}

.article-card,
.simple-explanation {
  max-width: 720px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(255, 254, 250, 0.82);
}

.article-card {
  margin-bottom: 14px;
  padding: 20px;
}

.article-card h2 {
  margin-bottom: 14px;
  font-size: 1.24rem;
  line-height: 1.36;
}

.simple-explanation {
  padding: 22px;
}

.simple-explanation h2 {
  margin-bottom: 12px;
  font-size: 1.12rem;
}

.simple-explanation p {
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.68;
}

.simple-explanation p:last-child {
  margin-bottom: 0;
  color: var(--ink);
  font-weight: 650;
}

@media (max-width: 640px) {
  .topbar,
  .compact-shell {
    width: min(100% - 28px, 820px);
  }

  .compact-shell {
    padding-top: 30px;
  }
}