:root {
  color-scheme: light;
  --bg: #f7f5ef;
  --surface: #ffffff;
  --surface-alt: #f0ebde;
  --text: #2f241d;
  --muted: #6f675f;
  --accent: #a66b3d;
  --border: #dfd2bc;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Hiragino Sans", "Yu Gothic UI", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

.app-header {
  background: linear-gradient(135deg, #5f3b1f, #a66b3d);
  color: white;
  padding: 24px 20px 28px;
}

.app-header h1 {
  margin: 0 0 8px;
  font-size: clamp(1.3rem, 3vw, 1.8rem);
}

.eyebrow {
  margin: 0 0 6px;
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.9;
}

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

.sidebar,
.content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.04);
}

.sidebar {
  padding: 18px;
  height: fit-content;
  position: sticky;
  top: 12px;
}

.sidebar h2 {
  margin-top: 0;
  font-size: 1rem;
}

.sidebar nav a {
  display: block;
  padding: 8px 0;
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}

.sidebar nav a:hover,
.sidebar nav a.active {
  color: var(--accent);
  font-weight: 600;
}

.future-note {
  margin-top: 16px;
  background: var(--surface-alt);
  padding: 12px;
  border-radius: 12px;
  font-size: 0.92rem;
}

.future-note ul {
  padding-left: 18px;
  margin-bottom: 0;
}

.content {
  padding: 20px 24px 32px;
  min-height: 70vh;
}

.status {
  color: var(--muted);
  margin-bottom: 12px;
}

.content h1,
.content h2,
.content h3 {
  color: var(--accent);
  line-height: 1.4;
}

.content img {
  max-width: 100%;
  height: auto;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0 20px;
  font-size: 0.95rem;
}

.content th,
.content td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

.content code {
  background: var(--surface-alt);
  padding: 0.15rem 0.3rem;
  border-radius: 4px;
}

@media (max-width: 768px) {
  .layout {
    grid-template-columns: 1fr;
    padding: 12px;
  }

  .sidebar {
    position: static;
  }

  .content {
    padding: 16px 16px 24px;
  }
}