/* style.css - エレクトロニクスI 学習サイト レスポンシブスタイル */

:root {
  --bg: #f1f5f9;
  --card: #ffffff;
  --ink: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --brand: #2563eb;
  --brand-soft: #dbeafe;
  --warn: #f59e0b;
  --warn-soft: #fef3c7;
  --danger: #ef4444;
  --danger-soft: #fee2e2;
  --ok: #10b981;
  --shadow: 0 1px 3px rgba(15,23,42,.08), 0 1px 2px rgba(15,23,42,.04);
  --radius: 12px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

/* ---------- ヘッダ ---------- */
.site-header {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: #fff;
  padding: 14px 16px;
  box-shadow: var(--shadow);
}
.site-header h1 {
  margin: 0;
  font-size: 1.15rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.site-header .sub {
  font-size: .8rem;
  opacity: .85;
  margin-top: 2px;
}

/* ---------- レイアウト ---------- */
.layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 16px;
  max-width: 1200px;
  margin: 16px auto;
  padding: 0 16px;
}
.sidebar, .main {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

/* ---------- サイドバー ---------- */
.sidebar { display: flex; flex-direction: column; max-height: calc(100vh - 120px); position: sticky; top: 16px; }
.side-section { padding: 12px; border-bottom: 1px solid var(--line); }
.side-section:last-child { border-bottom: none; }

.search-box { position: relative; }
.search-box i { position: absolute; left: 10px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: .8rem; }
#search-input {
  width: 100%;
  padding: 9px 12px 9px 30px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: .9rem;
  outline: none;
  transition: border-color .15s;
}
#search-input:focus { border-color: var(--brand); }

.cat-tabs { display: flex; flex-wrap: wrap; gap: 6px; }
.cat-tab {
  font-size: .72rem;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: var(--muted);
  cursor: pointer;
  transition: all .15s;
}
.cat-tab:hover { border-color: var(--brand); color: var(--brand); }
.cat-tab.active { background: var(--brand); color: #fff; border-color: var(--brand); }

.term-list { flex: 1; overflow-y: auto; padding: 6px; }
.term-item {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  text-align: left;
  background: transparent;
  border: none;
  border-radius: 8px;
  padding: 9px 10px;
  cursor: pointer;
  font-size: .88rem;
  color: var(--ink);
  transition: background .12s;
}
.term-item:hover { background: var(--brand-soft); }
.term-item.active { background: var(--brand); color: #fff; }
.term-item.active .term-sym { color: #fff; opacity: .8; }
.term-emoji { font-size: 1.1rem; width: 22px; text-align: center; flex-shrink: 0; }
.term-name { flex: 1; }
.term-sym { font-size: .72rem; color: var(--muted); background: #f1f5f9; padding: 1px 6px; border-radius: 4px; }
.term-item.active .term-sym { background: rgba(255,255,255,.2); }
.empty-hint { padding: 20px; text-align: center; color: var(--muted); font-size: .85rem; }

/* ---------- メインカード ---------- */
.main { padding: 18px; }
.term-card { animation: fade .25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.card-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding-bottom: 12px; border-bottom: 2px solid var(--line); }
.card-emoji { font-size: 2rem; }
.card-title-wrap { flex: 1; min-width: 160px; }
.card-title { margin: 0; font-size: 1.4rem; }
.card-reading { color: var(--muted); font-size: .85rem; }
.card-meta { display: flex; gap: 6px; flex-wrap: wrap; }
.meta-chip { font-size: .72rem; padding: 3px 8px; border-radius: 6px; }
.meta-chip.sym { background: var(--brand-soft); color: var(--brand); font-weight: 600; }
.meta-chip.unit { background: #f1f5f9; color: var(--ink); }
.meta-chip.cat { background: #ede9fe; color: #7c3aed; }

.one-line {
  background: var(--brand-soft);
  border-left: 4px solid var(--brand);
  padding: 12px 14px;
  border-radius: 8px;
  margin: 16px 0;
  font-size: 1rem;
  font-weight: 500;
}
.one-line i { color: var(--brand); opacity: .6; margin-right: 4px; }

.svg-box {
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px;
  margin: 16px 0;
  text-align: center;
  overflow-x: auto;
}
.term-svg { max-width: 100%; height: auto; display: inline-block; }
.svg-placeholder { color: var(--muted); padding: 40px; }

/* ---------- セクション ---------- */
.card-section {
  background: #f8fafc;
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 14px 0;
  border: 1px solid var(--line);
}
.card-section.warn { background: var(--warn-soft); border-color: #fcd34d; }
.sec-title { margin: 0 0 10px; font-size: 1rem; display: flex; align-items: center; gap: 8px; }
.card-section.warn .sec-title { color: #92400e; }
.sec-body { font-size: .9rem; }

.analogy { margin: 0; font-size: .95rem; }
.analogy::before { content: "💡 "; }

.principle { margin: 0; padding-left: 22px; }
.principle li { margin: 6px 0; }

.mistakes { margin: 0; padding-left: 22px; }
.mistakes li { margin: 6px 0; }
.mistakes li::marker { color: var(--danger); }

.compare-tbl { width: 100%; border-collapse: collapse; font-size: .88rem; }
.compare-tbl th, .compare-tbl td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; }
.compare-tbl th { background: var(--brand-soft); color: var(--brand); white-space: nowrap; width: 35%; }

.rel-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.rel-chip {
  font-size: .82rem;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid var(--brand);
  background: #fff;
  color: var(--brand);
  cursor: pointer;
  transition: all .15s;
}
.rel-chip:hover { background: var(--brand); color: #fff; }
.rel-chip.plain { border-color: var(--line); color: var(--muted); cursor: default; }
.rel-chip.plain:hover { background: #fff; color: var(--muted); }

/* ---------- ナビ ---------- */
.card-nav { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--line); }
.nav-btn {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  font-size: .85rem;
  color: var(--ink);
  transition: all .15s;
  text-align: left;
  flex: 0 0 auto;
}
.nav-btn.right { text-align: right; }
.nav-btn:hover { border-color: var(--brand); color: var(--brand); }
.nav-sub { font-size: .72rem; color: var(--muted); }
.nav-counter { color: var(--muted); font-size: .82rem; }

/* ---------- フッタ ---------- */
.site-footer { text-align: center; color: var(--muted); font-size: .78rem; padding: 24px 16px 40px; }

/* ---------- レスポンシブ ---------- */
@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; padding: 0 10px; }
  .sidebar { position: static; max-height: none; }
  .sidebar .term-list { max-height: 240px; }
  .main { padding: 14px; }
  .card-title { font-size: 1.2rem; }
  .card-nav { flex-wrap: wrap; }
  .nav-btn { flex: 1 1 40%; }
}

@media (max-width: 480px) {
  .site-header h1 { font-size: 1rem; }
  .card-emoji { font-size: 1.6rem; }
  .compare-tbl th, .compare-tbl td { font-size: .8rem; padding: 6px; }
  .meta-chip { font-size: .68rem; }
}