:root {
  color-scheme: light;
  --bg: #f6f7fb;
  --panel: #ffffff;
  --ink: #1e1d22;
  --muted: #6e6a78;
  --accent: #2f6ad8;
  --border: rgba(34, 32, 41, 0.16);
  --shadow: 0 10px 24px rgba(27, 25, 34, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family:
    "BIZ UDPGothic", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  color: var(--ink);
  background:
    linear-gradient(0deg, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0.8)),
    repeating-linear-gradient(
      45deg,
      rgba(47, 106, 216, 0.06) 0 12px,
      transparent 12px 24px
    ),
    var(--bg);
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.page {
  max-width: 1000px;
  margin: 0 auto;
  padding: 28px 20px 64px;
}

.site-header {
  margin-bottom: 20px;
}

.site-header h1 {
  margin: 6px 0;
  font-size: clamp(1.8rem, 2vw + 1.2rem, 2.6rem);
}

.badge {
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.lead {
  margin: 8px 0 0;
  color: var(--muted);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  color: var(--muted);
  font-size: 0.9rem;
}

.category-grid {
  display: grid;
  gap: 16px;
}

.category {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow);
}

.category-title {
  margin: 0 0 12px;
  font-size: 1.1rem;
}

.board-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.board-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid transparent;
  color: var(--ink);
}

.board-link::before {
  content: "";
  width: 10px;
  height: 10px;
  border: 2px solid var(--accent);
  border-radius: 2px;
  display: inline-block;
}

.board-link:hover {
  border-color: var(--accent);
  background: rgba(47, 106, 216, 0.06);
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  box-shadow: var(--shadow);
  margin-bottom: 18px;
}

.panel-header {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 12px;
}

.panel-help {
  color: var(--muted);
  font-size: 0.9rem;
}

.form-grid {
  display: grid;
  gap: 12px;
}

label {
  display: grid;
  gap: 6px;
  font-size: 0.9rem;
  color: var(--muted);
}

input,
textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fdfdff;
  font-size: 1rem;
}

textarea {
  min-height: 130px;
  resize: vertical;
}

button {
  border: none;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  width: fit-content;
}

.thread-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 6px;
}

.thread-link {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid transparent;
  color: var(--ink);
}

.thread-link:hover {
  border-color: var(--accent);
  background: rgba(47, 106, 216, 0.06);
}

.thread-meta {
  color: var(--muted);
  font-size: 0.85rem;
  white-space: nowrap;
}

.post-list {
  display: grid;
  gap: 12px;
}

.post {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
}

.post-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 6px;
}

.post-body {
  white-space: normal;
}

.empty {
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-note {
  margin-top: 16px;
  color: var(--muted);
  font-size: 0.85rem;
}

@media (max-width: 760px) {
  .thread-link {
    flex-direction: column;
    align-items: flex-start;
  }

  button {
    width: 100%;
  }
}

@media (min-width: 840px) {
  .category-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}