:root {
  --bg: #f5f7fb;
  --bg-card: #ffffff;
  --bg-sub: #eef2f8;
  --fg: #1a1a1a;
  --fg-sub: #5a6470;
  --accent: #0a6cba;
  --accent-strong: #064a82;
  --border: #d8e0eb;
  --danger: #c73030;
  --warn: #d97706;
  --ok: #128a4e;
  --header-h: 56px;
  --sidebar-w: 280px;
}

[data-theme="dark"] {
  --bg: #0a1620;
  --bg-card: #142434;
  --bg-sub: #1c2f44;
  --fg: #e8eef5;
  --fg-sub: #95a5b8;
  --accent: #4ba3e8;
  --accent-strong: #7cc1f0;
  --border: #2a3f55;
  --danger: #e26565;
  --warn: #f5a13b;
  --ok: #4dc97f;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Yu Gothic UI", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

input, select, textarea {
  font: inherit;
  color: inherit;
}

/* === 認証画面 === */
.auth-screen {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #0a1e3c 0%, #1a4a7c 100%);
  z-index: 1000;
  padding: 20px;
}

.auth-box {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  padding: 40px 30px;
  max-width: 360px;
  width: 100%;
  text-align: center;
  color: #fff;
}

.auth-icon { font-size: 56px; margin-bottom: 12px; }
.auth-box h1 { margin: 0 0 8px; font-size: 22px; }
.auth-sub { color: rgba(255, 255, 255, 0.7); margin: 0 0 24px; font-size: 14px; }
.auth-box input {
  width: 100%;
  padding: 14px 16px;
  font-size: 16px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  border-radius: 10px;
  margin-bottom: 12px;
}
.auth-box input:focus {
  outline: none;
  border-color: #4ba3e8;
}
.auth-box button {
  width: 100%;
  padding: 14px;
  font-size: 16px;
  border: none;
  background: #4ba3e8;
  color: #fff;
  border-radius: 10px;
  font-weight: 600;
  margin-top: 4px;
}
.auth-box button:hover { background: #5ab3f8; }
.auth-error {
  color: #ffacac;
  font-size: 13px;
  margin: 8px 0 0;
}

/* === ヘッダー === */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 12px;
  z-index: 50;
}
.menu-btn, .theme-btn, .close-btn {
  background: none;
  border: none;
  font-size: 22px;
  padding: 8px 12px;
  color: var(--fg);
  border-radius: 8px;
}
.menu-btn:hover, .theme-btn:hover { background: var(--bg-sub); }
.header-title {
  flex: 1;
  text-align: center;
  font-weight: 600;
  font-size: 16px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  padding: 0 8px;
}

/* === サイドバー === */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--sidebar-w);
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  transform: translateX(-100%);
  transition: transform 0.25s ease;
  z-index: 100;
  display: flex;
  flex-direction: column;
}
.sidebar.open { transform: translateX(0); }

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}
.close-btn { font-size: 28px; line-height: 1; }

.search-box { padding: 12px 16px; border-bottom: 1px solid var(--border); }
.search-box input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-sub);
}
.search-box input:focus { outline: none; border-color: var(--accent); }

.nav-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 0;
}
.nav-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 18px;
  background: none;
  border: none;
  color: var(--fg);
  font-size: 14.5px;
  border-left: 3px solid transparent;
}
.nav-item:hover { background: var(--bg-sub); }
.nav-item.active {
  background: var(--bg-sub);
  border-left-color: var(--accent);
  font-weight: 600;
  color: var(--accent);
}
.nav-group-title {
  padding: 14px 18px 6px;
  font-size: 11px;
  color: var(--fg-sub);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 700;
}

.sidebar-footer {
  border-top: 1px solid var(--border);
  padding: 12px;
  display: flex;
  gap: 8px;
}
.footer-btn {
  flex: 1;
  padding: 10px;
  font-size: 13px;
  background: var(--bg-sub);
  border: 1px solid var(--border);
  color: var(--fg-sub);
  border-radius: 8px;
}
.footer-btn:hover { color: var(--fg); }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 90;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.overlay.show { opacity: 1; pointer-events: auto; }

/* === メイン === */
.main {
  padding: calc(var(--header-h) + 16px) 16px 60px;
  max-width: 880px;
  margin: 0 auto;
}

@media (min-width: 900px) {
  .sidebar { transform: translateX(0); }
  .main { margin-left: var(--sidebar-w); }
  .menu-btn, .close-btn { display: none; }
  .overlay { display: none; }
}

/* === コンテンツ === */
#content-view h1 {
  font-size: 26px;
  margin: 0 0 8px;
  display: flex;
  align-items: center;
  gap: 10px;
}
#content-view h2 {
  font-size: 19px;
  margin: 28px 0 10px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--accent);
}
#content-view h3 {
  font-size: 16px;
  margin: 20px 0 8px;
  color: var(--accent);
}
#content-view p { margin: 8px 0; }
#content-view ul, #content-view ol { padding-left: 22px; margin: 8px 0; }
#content-view li { margin: 4px 0; }

#content-view code {
  background: var(--bg-sub);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.92em;
  font-family: "SF Mono", Consolas, monospace;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 18px;
  margin: 12px 0;
}
.card.rule {
  border-left: 4px solid var(--danger);
  background: linear-gradient(to right, color-mix(in srgb, var(--danger) 8%, var(--bg-card)) 0%, var(--bg-card) 30%);
}
.card.warn {
  border-left: 4px solid var(--warn);
  background: linear-gradient(to right, color-mix(in srgb, var(--warn) 8%, var(--bg-card)) 0%, var(--bg-card) 30%);
}
.card.tip {
  border-left: 4px solid var(--ok);
  background: linear-gradient(to right, color-mix(in srgb, var(--ok) 8%, var(--bg-card)) 0%, var(--bg-card) 30%);
}
.card-title {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 6px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 14px;
}
th, td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
}
th {
  background: var(--bg-sub);
  font-weight: 600;
  font-size: 13px;
}
td.num {
  font-family: "SF Mono", Consolas, monospace;
  white-space: nowrap;
}

.kbd-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
  margin: 12px 0;
}
.kbd {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  text-align: center;
}
.kbd-num {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent);
  font-family: "SF Mono", Consolas, monospace;
}
.kbd-label {
  font-size: 12px;
  color: var(--fg-sub);
  margin-top: 4px;
}

/* === クイズ === */
.quiz-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  margin: 12px 0;
}
.quiz-q {
  font-weight: 600;
  margin-bottom: 8px;
}
.quiz-answer {
  background: var(--bg-sub);
  border-radius: 8px;
  padding: 10px 12px;
  margin-top: 10px;
  font-size: 14px;
  color: var(--fg-sub);
  display: none;
}
.quiz-answer.show { display: block; }
.quiz-answer strong { color: var(--accent); }
.quiz-toggle {
  background: var(--bg-sub);
  border: 1px solid var(--border);
  color: var(--fg-sub);
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 13px;
  margin-right: 6px;
}
.quiz-toggle:hover { color: var(--fg); }
.quiz-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.mark-btn {
  background: var(--bg-sub);
  border: 1px solid var(--border);
  color: var(--fg-sub);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 12px;
}
.mark-btn.active.know { background: color-mix(in srgb, var(--ok) 20%, var(--bg-sub)); color: var(--ok); border-color: var(--ok); }
.mark-btn.active.weak { background: color-mix(in srgb, var(--warn) 20%, var(--bg-sub)); color: var(--warn); border-color: var(--warn); }

/* === 検索結果 === */
#search-results {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 16px;
}
.search-result-item {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
}
.search-result-item:last-child { border-bottom: none; }
.search-result-item:hover { background: var(--bg-sub); }
.search-result-section {
  font-size: 12px;
  color: var(--fg-sub);
  margin-bottom: 4px;
}
.search-result-snippet mark {
  background: color-mix(in srgb, var(--warn) 40%, transparent);
  color: inherit;
  padding: 1px 2px;
  border-radius: 2px;
}

/* === フローチャート === */
.flow {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 14px 0;
}
.flow-step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 12px 14px;
  position: relative;
}
.flow-step::after {
  content: "↓";
  position: absolute;
  bottom: -15px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--accent);
  font-size: 18px;
  font-weight: bold;
}
.flow-step:last-child::after { display: none; }
.flow-step-num {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  text-align: center;
  line-height: 22px;
  font-size: 12px;
  margin-right: 8px;
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
  background: var(--bg-sub);
  color: var(--fg-sub);
  margin-left: 6px;
}
.badge.danger { background: color-mix(in srgb, var(--danger) 20%, transparent); color: var(--danger); }
.badge.warn { background: color-mix(in srgb, var(--warn) 20%, transparent); color: var(--warn); }
.badge.ok { background: color-mix(in srgb, var(--ok) 20%, transparent); color: var(--ok); }

/* ハイライト用（マークされたものを少し目立たせる） */
.section-meta {
  font-size: 12px;
  color: var(--fg-sub);
  margin-bottom: 12px;
}

hr { border: 0; border-top: 1px solid var(--border); margin: 24px 0; }