/* style.css — all styling */
:root {
  color-scheme: dark;
  --bg: #0e1116;
  --bg-2: #151a22;
  --panel: #1a2029;
  --panel-2: #202834;
  --border: #2a3340;
  --border-strong: #3a4655;
  --text: #e8edf3;
  --text-dim: #9aa6b5;
  --text-faint: #6b7785;
  --accent: #5b9cff;
  --accent-soft: rgba(91, 156, 255, 0.14);
  --accent-glow: rgba(91, 156, 255, 0.35);
  --metric: #4cc9a0;
  --imperial: #f0a96f;
  --danger: #ff6b6b;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 6px 22px rgba(0,0,0,0.35);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Roboto Mono", ui-monospace, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    color-scheme: light;
    --bg: #f4f6fa;
    --bg-2: #eaeef4;
    --panel: #ffffff;
    --panel-2: #f7f9fc;
    --border: #e1e6ee;
    --border-strong: #cdd5e0;
    --text: #1a2230;
    --text-dim: #5a6678;
    --text-faint: #8a96a8;
    --accent: #2f7de0;
    --accent-soft: rgba(47, 125, 224, 0.10);
    --accent-glow: rgba(47, 125, 224, 0.28);
    --metric: #1f9d78;
    --imperial: #d68445;
    --shadow: 0 6px 22px rgba(20,30,50,0.10);
  }
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0e1116;
  --bg-2: #151a22;
  --panel: #1a2029;
  --panel-2: #202834;
  --border: #2a3340;
  --border-strong: #3a4655;
  --text: #e8edf3;
  --text-dim: #9aa6b5;
  --text-faint: #6b7785;
  --accent: #5b9cff;
  --accent-soft: rgba(91, 156, 255, 0.14);
  --accent-glow: rgba(91, 156, 255, 0.35);
  --metric: #4cc9a0;
  --imperial: #f0a96f;
  --shadow: 0 6px 22px rgba(0,0,0,0.35);
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f4f6fa;
  --bg-2: #eaeef4;
  --panel: #ffffff;
  --panel-2: #f7f9fc;
  --border: #e1e6ee;
  --border-strong: #cdd5e0;
  --text: #1a2230;
  --text-dim: #5a6678;
  --text-faint: #8a96a8;
  --accent: #2f7de0;
  --accent-soft: rgba(47, 125, 224, 0.10);
  --accent-glow: rgba(47, 125, 224, 0.28);
  --metric: #1f9d78;
  --imperial: #d68445;
  --shadow: 0 6px 22px rgba(20,30,50,0.10);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow: hidden;
  touch-action: manipulation;
}

.app {
  height: 100%;
  display: flex;
  flex-direction: column;
  max-width: 980px;
  margin: 0 auto;
  padding: 14px 16px 18px;
  gap: 14px;
}

/* ---------- Top bar ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), #8a6bff);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 22px;
  font-weight: 700;
  box-shadow: 0 4px 14px var(--accent-glow);
}

.brand-text h1 {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.brand-text .tag {
  margin: 1px 0 0;
  font-size: 12px;
  color: var(--text-dim);
}

.sys-toggle {
  display: inline-flex;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 3px;
  gap: 2px;
}

.sys-toggle button {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  padding: 7px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.18s, color 0.18s;
}

.sys-toggle button:hover { color: var(--text); }
.sys-toggle button.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px var(--accent-glow);
}

/* ---------- Categories ---------- */
.cats {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 2px 1px 6px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.cats::-webkit-scrollbar { height: 6px; }
.cats::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 999px; }

.cat {
  flex: 0 0 auto;
  appearance: none;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text-dim);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  padding: 9px 14px;
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  white-space: nowrap;
  transition: all 0.18s ease;
}

.cat:hover { color: var(--text); border-color: var(--border-strong); }
.cat.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

.cat-icon { font-size: 15px; }

/* ---------- Converter ---------- */
.converter {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.panel {
  flex: 1 1 220px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  box-shadow: var(--shadow);
  min-width: 0;
}

.field-label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 8px;
}

.field-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.value-input {
  flex: 1 1 auto;
  min-width: 0;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 600;
  padding: 10px 12px;
  outline: none;
  transition: border-color 0.18s, box-shadow 0.18s;
}

.value-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.unit-select {
  flex: 0 1 auto;
  min-width: 120px;
  max-width: 180px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 10px 10px;
  outline: none;
  cursor: pointer;
  transition: border-color 0.18s;
  -webkit-appearance: none;
  appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--text-dim) 50%),
    linear-gradient(135deg, var(--text-dim) 50%, transparent 50%);
  background-position: calc(100% - 16px) center, calc(100% - 11px) center;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 28px;
}

.unit-select:focus { border-color: var(--accent); }
.unit-select option { background: var(--panel); color: var(--text); }

.swap-btn {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--accent);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  transition: transform 0.25s ease, background 0.18s, border-color 0.18s;
}

.swap-btn:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
  transform: rotate(180deg);
}

.swap-btn:active { transform: rotate(180deg) scale(0.92); }

/* ---------- Reference grid ---------- */
.reference {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.ref-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 0 2px;
}

.ref-head h2 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: capitalize;
}

.ref-head h2 #catName { color: var(--text); }

.ref-hint {
  margin: 0;
  font-size: 12px;
  color: var(--text-faint);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 10px;
  overflow-y: auto;
  padding: 2px 2px 4px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.grid::-webkit-scrollbar { width: 8px; }
.grid::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 999px; }

.card {
  appearance: none;
  text-align: left;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 12px 13px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: transform 0.15s ease, border-color 0.15s, background 0.15s, box-shadow 0.15s;
  min-width: 0;
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
}

.card:active { transform: translateY(0) scale(0.99); }

.card.selected {
  border-color: var(--accent);
  background: linear-gradient(180deg, var(--accent-soft), var(--panel));
  box-shadow: 0 0 0 1px var(--accent), 0 6px 18px var(--accent-glow);
}

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.card-sym {
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-val {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
  word-break: break-all;
  line-height: 1.2;
}

.card-val.accent { color: var(--accent); }

.card-name {
  font-size: 11px;
  color: var(--text-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tag {
  font-size: 9px;
  font-weight: 800;
  letter-spacing: 0.04em;
  padding: 2px 5px;
  border-radius: 4px;
  flex: 0 0 auto;
}

.tag-m { background: rgba(76, 201, 160, 0.16); color: var(--metric); }
.tag-i { background: rgba(240, 169, 111, 0.16); color: var(--imperial); }

/* ---------- Responsive ---------- */
@media (max-width: 560px) {
  .app { padding: 10px 10px 12px; gap: 10px; }
  .topbar { gap: 8px; }
  .brand-text h1 { font-size: 17px; }
  .brand-text .tag { font-size: 11px; }
  .logo { width: 36px; height: 36px; font-size: 19px; border-radius: 10px; }
  .sys-toggle button { padding: 6px 11px; font-size: 12px; }
  .converter { gap: 8px; }
  .panel { padding: 12px 13px; }
  .value-input { font-size: 19px; padding: 9px 10px; }
  .unit-select { font-size: 13px; min-width: 100px; }
  .swap-btn { width: 40px; height: 40px; }
  .grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 8px; }
  .card { padding: 11px 12px; }
  .card-val { font-size: 16px; }
}

@media (max-width: 380px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
  .sys-toggle button { padding: 6px 9px; }
}