:root {
  --paper: #FBF8F1;
  --ink: #22302C;
  --ink-soft: rgba(34, 48, 44, 0.64);
  --ink-faint: rgba(34, 48, 44, 0.40);
  --line: rgba(34, 48, 44, 0.10);
  --accent: #4C7A63;
  --card: rgba(34, 48, 44, 0.03);
  --nav-bg: rgba(251, 248, 241, 0.86);
  --btn-bg: rgba(255, 255, 255, 0.6);
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #141A18;
    --ink: #EDE9DF;
    --ink-soft: rgba(237, 233, 223, 0.66);
    --ink-faint: rgba(237, 233, 223, 0.42);
    --line: rgba(237, 233, 223, 0.12);
    --accent: #8FBF9F;
    --card: rgba(237, 233, 223, 0.04);
    --nav-bg: rgba(20, 26, 24, 0.86);
    --btn-bg: rgba(237, 233, 223, 0.06);
  }
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; overflow-x: clip; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.8;
  padding-bottom: 72px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-wrap: break-word;
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
}

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-weight: 600;
  font-size: 17px;
  letter-spacing: 0.10em;
  text-decoration: none;
  color: var(--ink);
}

.nav-links { display: flex; gap: 18px; }

.nav-links a { color: var(--ink-soft); text-decoration: none; font-size: 14px; }
.nav-links a:hover { color: var(--accent); }

main { max-width: 860px; margin: 0 auto; padding: 40px 24px 0; }

h1 { font-size: 28px; font-weight: 600; letter-spacing: 0.04em; margin-bottom: 6px; }

.updated { color: var(--ink-faint); font-size: 13px; margin-bottom: 26px; }

h2 { font-size: 17px; font-weight: 600; margin: 30px 0 10px; }

p, li { color: var(--ink-soft); font-size: 15px; }

ul { padding-left: 20px; margin: 8px 0; }
li { margin: 6px 0; }

a { color: var(--accent); }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 20px 22px;
  margin: 22px 0;
}

.placeholder {
  min-height: 56vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 12px;
}

.placeholder h1 { font-size: 34px; letter-spacing: 0.16em; }
.placeholder p { max-width: 420px; }

.actions { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; margin-top: 10px; }

.btn {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--btn-bg);
  color: var(--ink);
  text-decoration: none;
  font-size: 14px;
}

.btn.primary { background: var(--accent); border-color: var(--accent); color: #FBF8F1; }

footer {
  max-width: 860px;
  margin: 56px auto 0;
  padding: 20px 24px 0;
  border-top: 1px solid var(--line);
  color: var(--ink-faint);
  font-size: 13px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: space-between;
}

footer a { color: var(--ink-faint); text-decoration: none; }
footer a:hover { color: var(--accent); }