:root {
  color-scheme: light;
  --bg: #f7f7f8;
  --card-bg: #ffffff;
  --text: #1c1c1e;
  --muted: #6b6b70;
  --accent: #2b6cb0;
  --border: #e3e3e6;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
}

header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  padding: 16px 20px;
  position: sticky;
  top: 0;
  z-index: 10;
}

header .inner {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}

header .brand {
  font-weight: 700;
  font-size: 18px;
  margin-right: auto;
}

nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 15px;
  white-space: nowrap;
}

nav a:hover {
  background: var(--bg);
}

nav a.active {
  color: var(--accent);
  background: #e8f0fb;
  font-weight: 600;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

h1 {
  font-size: 22px;
  margin: 0 0 20px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  margin-bottom: 16px;
}

.post-date {
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 10px;
}

.post-body {
  white-space: pre-wrap;
  word-wrap: break-word;
  font-size: 15px;
}

ul.file-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul.file-list li {
  margin-bottom: 10px;
}

ul.file-list a {
  display: block;
  color: var(--text);
  text-decoration: none;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  font-size: 15px;
}

ul.file-list a:hover {
  border-color: var(--accent);
}

.empty-state {
  color: var(--muted);
  text-align: center;
  padding: 40px 0;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #15161a;
    --card-bg: #1e1f24;
    --text: #e8e8ea;
    --muted: #93939a;
    --accent: #6ea8ea;
    --border: #2c2d33;
  }

  nav a.active {
    background: #1c2a3a;
  }
}