/* ==========================================================================
   Design tokens
   ========================================================================== */
:root{
  --bg: #fafaf9;
  --bg-elevated: #ffffff;
  --border: #e4e2dd;
  --text: #1c1b1a;
  --text-muted: #6b6862;
  --text-faint: #9c9890;
  --accent: #2563eb;
  --accent-soft: #eaf1ff;
  --accent-contrast: #ffffff;

  --badge-excel-bg: #e8f3ea;
  --badge-excel-text: #1e7a34;
  --badge-sheets-bg: #e7f0fe;
  --badge-sheets-text: #1a56c4;
  --badge-sql-bg: #fdeee6;
  --badge-sql-text: #b1490f;
  --badge-pivot-bg: #f3e9fb;
  --badge-pivot-text: #7228a8;
  --badge-shortcut-bg: #fbeee9;
  --badge-shortcut-text: #a4451c;

  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 1px 2px rgba(20,18,14,0.06), 0 1px 1px rgba(20,18,14,0.04);
  --mono: "SF Mono", "JetBrains Mono", "Fira Code", Consolas, "Courier New", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --sidebar-w: 250px;
  --topbar-h: 64px;
  --filterbar-h: 52px;
}

@media (prefers-color-scheme: dark){
  :root{
    --bg: #161513;
    --bg-elevated: #1e1d1a;
    --border: #34322c;
    --text: #ede9e2;
    --text-muted: #a8a399;
    --text-faint: #726d63;
    --accent: #5b9bff;
    --accent-soft: #1a2b47;
    --accent-contrast: #0b1220;

    --badge-excel-bg: #17331f;
    --badge-excel-text: #7fdb96;
    --badge-sheets-bg: #16233f;
    --badge-sheets-text: #8fb6ff;
    --badge-sql-bg: #3a2417;
    --badge-sql-text: #f4a877;
    --badge-pivot-bg: #2c1f3a;
    --badge-pivot-text: #cfa3f2;
    --badge-shortcut-bg: #3a2318;
    --badge-shortcut-text: #f3a582;

    --shadow: 0 1px 2px rgba(0,0,0,0.4);
  }
}

*{ box-sizing: border-box; }
html,body{ margin:0; padding:0; }
body{
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}
code, .mono, .formula, .syntax{ font-family: var(--mono); }

a{ color: var(--accent); }

.topbar{
  height: var(--topbar-h);
  display:flex;
  align-items:center;
  gap: 14px;
  padding: 0 18px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-elevated);
  position: sticky;
  top: 0;
  z-index: 40;
}
.nav-toggle{
  display:none;
  background:none;
  border:1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 18px;
  width: 38px;
  height: 38px;
  cursor:pointer;
  color: var(--text);
}
.brand{ display:flex; align-items:center; gap:8px; font-weight:700; font-size:16px; white-space:nowrap; }
.brand-mark{ color: var(--accent); font-size: 20px; }
.search-wrap{ flex:1; position:relative; max-width: 640px; }
#searchInput{
  width:100%;
  padding: 10px 40px 10px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  outline: none;
  transition: border-color .15s;
}
#searchInput:focus{ border-color: var(--accent); }
.search-count{
  position:absolute;
  right:12px;
  top:50%;
  transform:translateY(-50%);
  font-size:12px;
  color: var(--text-faint);
  pointer-events:none;
}

.filter-bar{
  height: var(--filterbar-h);
  display:flex;
  align-items:center;
  gap:8px;
  padding: 0 18px;
  overflow-x:auto;
  border-bottom: 1px solid var(--border);
  background: var(--bg-elevated);
  position: sticky;
  top: var(--topbar-h);
  z-index: 39;
  scrollbar-width: none;
}
.filter-bar::-webkit-scrollbar{ display:none; }
.chip{
  flex-shrink:0;
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  cursor:pointer;
  transition: all .12s;
}
.chip:hover{ border-color: var(--accent); color: var(--accent); }
.chip.active{ background: var(--accent); color: var(--accent-contrast); border-color: var(--accent); }

.layout{
  display:flex;
  max-width: 1400px;
  margin: 0 auto;
}
.sidebar{
  width: var(--sidebar-w);
  flex-shrink:0;
  position: sticky;
  top: calc(var(--topbar-h) + var(--filterbar-h));
  height: calc(100vh - var(--topbar-h) - var(--filterbar-h));
  overflow-y:auto;
  border-right: 1px solid var(--border);
  padding: 18px 8px;
}
.sidebar-inner .side-group{ margin-bottom: 4px; }
.sidebar-inner .side-group-title{
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: 14px 12px 6px;
}
.side-link{
  display:flex;
  justify-content:space-between;
  gap:6px;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  text-decoration:none;
  font-size: 13.5px;
  cursor:pointer;
}
.side-link:hover{ background: var(--accent-soft); color: var(--accent); }
.side-link .count{ color: var(--text-faint); font-size: 12px; }

.content{
  flex:1;
  min-width:0;
  max-width: 100%;
  overflow-x: hidden;
  padding: 24px 28px 80px;
}

.main-section-title{
  font-size: 26px;
  font-weight: 800;
  margin: 36px 0 4px;
  scroll-margin-top: 140px;
}
.main-section-title:first-child{ margin-top: 4px; }
.main-section-sub{
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 20px;
}
.group-title{
  font-size: 18px;
  font-weight: 700;
  margin: 28px 0 12px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  scroll-margin-top: 140px;
}
.group-title:first-of-type{ border-top:none; }

.card-grid{
  display:grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 14px;
}
.card{
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 16px 14px;
  box-shadow: var(--shadow);
  display:flex;
  flex-direction:column;
  gap: 8px;
  min-width: 0;
  overflow: hidden;
}
.card-head{
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap: 8px;
}
.card-name{
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 700;
}
.badges{ display:flex; gap:5px; flex-wrap:wrap; justify-content:flex-end; }
.badge{
  font-size: 10.5px;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 999px;
  white-space:nowrap;
  letter-spacing: .02em;
}
.badge-excel{ background: var(--badge-excel-bg); color: var(--badge-excel-text); }
.badge-sheets{ background: var(--badge-sheets-bg); color: var(--badge-sheets-text); }
.badge-sql{ background: var(--badge-sql-bg); color: var(--badge-sql-text); }
.badge-pivot{ background: var(--badge-pivot-bg); color: var(--badge-pivot-text); }
.badge-shortcut{ background: var(--badge-shortcut-bg); color: var(--badge-shortcut-text); }

.syntax-row{
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  font-size: 13px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 8px;
}
.syntax-text{ overflow-x:auto; white-space: pre; flex:1; min-width:0; }
.copy-btn{
  flex-shrink:0;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  width: 28px;
  height: 28px;
  font-size: 13px;
  cursor: pointer;
  display:flex;
  align-items:center;
  justify-content:center;
  transition: all .12s;
}
.copy-btn:hover{ border-color: var(--accent); color: var(--accent); }
.copy-btn.copied{ background: var(--accent); color:var(--accent-contrast); border-color:var(--accent); }

.card-desc{ color: var(--text); font-size: 13.5px; }
.card-example{ font-size: 12.5px; color: var(--text-muted); background: var(--bg); border-left: 3px solid var(--accent); border-radius: 4px; padding: 6px 10px; }
.card-example b{ color: var(--text); font-weight:600; }
.card-example code{ background: var(--accent-soft); padding: 1px 5px; border-radius:4px; color: var(--text); }
.card-note{ font-size: 12px; color: var(--text-faint); border-top: 1px dashed var(--border); padding-top: 7px; margin-top: 2px; }
.card-note strong{ color: var(--text-muted); }

.venn{ display:flex; align-items:center; justify-content:center; padding: 4px 0; }
.venn svg{ max-width: 140px; }

.steps{ margin: 6px 0 0; padding-left: 20px; font-size: 13px; color: var(--text-muted); }
.steps li{ margin-bottom: 3px; }

.shortcut-table-wrap{ overflow-x:auto; margin-bottom: 26px; border: 1px solid var(--border); border-radius: var(--radius); }
table.shortcuts{ width:100%; border-collapse: collapse; font-size: 13px; background: var(--bg-elevated); }
table.shortcuts caption{ text-align:left; font-weight:700; font-size:14px; padding: 10px 14px; background: var(--bg); border-bottom: 1px solid var(--border); }
table.shortcuts th, table.shortcuts td{ padding: 8px 12px; border-bottom: 1px solid var(--border); text-align:left; vertical-align: top; }
table.shortcuts th{ color: var(--text-faint); font-size: 11px; text-transform: uppercase; letter-spacing:.03em; font-weight:700; }
table.shortcuts td.key{ font-family: var(--mono); white-space:nowrap; }
table.shortcuts tr:last-child td{ border-bottom:none; }
table.shortcuts tbody tr:hover{ background: var(--accent-soft); }

.hidden{ display:none !important; }
.empty-state{ text-align:center; padding: 60px 20px; color: var(--text-faint); font-size: 15px; }
.toast{
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: var(--bg);
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 13px;
  font-weight:600;
  opacity: 0;
  pointer-events:none;
  transition: all .18s;
  z-index: 100;
}
.toast.show{ opacity: 1; transform: translateX(-50%) translateY(0); }

mark.hit{ background: #ffe28a; color:#1c1b1a; border-radius:3px; padding: 0 1px; }
@media (prefers-color-scheme: dark){ mark.hit{ background:#8a6d1f; color:#fff; } }

@media (max-width: 900px){
  :root{ --topbar-h: 56px; }
  .nav-toggle{ display:flex; align-items:center; justify-content:center; }
  .brand-text{ display:none; }
  .sidebar{
    position: fixed;
    left: 0;
    top: calc(var(--topbar-h) + var(--filterbar-h));
    height: calc(100vh - var(--topbar-h) - var(--filterbar-h));
    background: var(--bg-elevated);
    transform: translateX(-100%);
    transition: transform .2s ease;
    z-index: 50;
    box-shadow: var(--shadow);
  }
  .sidebar.open{ transform: translateX(0); }
  .content{ padding: 18px 14px 80px; }
  .card-grid{ grid-template-columns: 1fr; }
  .main-section-title{ font-size: 22px; }
}