:root {
  --accent: #007AFF;
  --bg: #f2f2f7;
  --surface: #ffffff;
  --surface-2: #ffffff;
  --text: #1c1c1e;
  --text-secondary: #6c6c70;
  --border: rgba(60, 60, 67, 0.29);
  --danger: #ff3b30;
  --warning: #ff9500;
  --shadow: rgba(0, 0, 0, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #000000;
    --surface: #1c1c1e;
    --surface-2: #2c2c2e;
    --text: #f2f2f7;
    --text-secondary: #98989f;
    --border: rgba(84, 84, 88, 0.6);
    --shadow: rgba(0, 0, 0, 0.4);
  }
}

:root[data-theme="dark"] {
  --bg: #000000;
  --surface: #1c1c1e;
  --surface-2: #2c2c2e;
  --text: #f2f2f7;
  --text-secondary: #98989f;
  --border: rgba(84, 84, 88, 0.6);
  --shadow: rgba(0, 0, 0, 0.4);
}

* { box-sizing: border-box; }

html {
  min-height: 100%;
  background:
    radial-gradient(circle at 50% 0%, color-mix(in srgb, var(--accent) 14%, transparent), transparent 60%) fixed,
    var(--bg);
}

body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.page {
  max-width: 640px;
  margin: 0 auto;
  min-height: 100vh;
  padding: 0 0 48px;
}

#pageHeader {
  display: contents;
}

.site-title {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 16px 4px;
  font-size: 24px;
  font-weight: 800;
  color: var(--accent);
}

.site-logo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: cover;
  flex: 0 0 auto;
}

.tabbar {
  display: flex;
  overflow-x: auto;
  scrollbar-width: none;
  gap: 2px;
  padding: 10px 10px 0;
  position: sticky;
  top: 0;
  z-index: 10;
  background:
    radial-gradient(circle at 50% 0%, color-mix(in srgb, var(--accent) 14%, transparent), transparent 60%) fixed,
    var(--bg);
  border-bottom: 1px solid var(--accent);
}

.tabbar::-webkit-scrollbar { display: none; }

.tab {
  flex: 0 0 auto;
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  text-decoration: none;
  white-space: nowrap;
  border-radius: 10px 10px 0 0;
  border-bottom: 2px solid transparent;
}

.tab.active {
  color: var(--accent);
  background: var(--surface);
  border-bottom: 2px solid var(--accent);
}

.reset-bar {
  display: flex;
  justify-content: center;
  padding: 8px 16px 24px;
}

.btn-reset {
  min-width: 160px;
  padding: 12px 28px;
  border-radius: 12px;
  border: 1px solid var(--danger);
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  color: var(--danger);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}

.btn-reset:active {
  background: color-mix(in srgb, var(--danger) 24%, transparent);
}

main {
  padding: 16px;
}

.card {
  background: var(--surface);
  border-radius: 14px;
  box-shadow: 0 2px 10px var(--shadow);
  margin-bottom: 16px;
  overflow: hidden;
}

.card-header {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
  padding: 12px 16px 4px;
}

.card-footer {
  font-size: 12px;
  color: var(--text-secondary);
  padding: 6px 16px 14px;
}

.field-block {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
}

.field-block:last-child { border-bottom: none; }

.field-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
}

.field-block .field-row {
  padding: 0;
  border-bottom: none;
}

.card > .field-row:last-child,
.card > a:last-child .field-row {
  border-bottom: none;
}

.field-row.no-divider {
  border-bottom: none;
}

.card.no-dividers .field-row,
.card.no-dividers .field-block {
  border-bottom: none;
}

.field-label {
  font-size: 16px;
  white-space: nowrap;
}

.field-unit {
  color: var(--text-secondary);
  font-size: 13px;
  margin-left: 4px;
}

.field-input-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.num-input {
  width: 100px;
  text-align: right;
  font-size: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-2);
  color: var(--text);
  padding: 6px 10px;
  font-variant-numeric: tabular-nums;
}

.num-input:focus {
  outline: none;
  border-color: var(--accent);
}

.text-input {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-2);
  color: var(--text);
  font-size: 16px;
  padding: 6px 10px;
}

.text-input:focus {
  outline: none;
  border-color: var(--accent);
}

.toggle-btn {
  min-width: 64px;
  padding: 6px 12px;
  border-radius: 8px;
  border: none;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.toggle-btn.imperial {
  background: color-mix(in srgb, var(--danger) 40%, transparent);
  color: #ffffff;
}

.toggle-btn.static {
  display: inline-block;
  text-align: center;
  cursor: default;
}

.result-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 14px 16px;
  background: color-mix(in srgb, var(--accent) 50%, var(--surface));
  font-weight: 700;
  color: #ffffff;
}

.result-row .value {
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.result-row .unit {
  font-weight: 400;
  font-size: 13px;
  opacity: 0.85;
}

.result-row .placeholder {
  font-weight: 300;
  opacity: 0.8;
}

.error-text {
  color: var(--danger);
  font-size: 12px;
  padding: 2px 16px 6px;
}

.warning-text {
  color: var(--warning);
  font-size: 12px;
  font-weight: 600;
  padding: 2px 16px 6px;
}

.hint-text {
  color: var(--text-secondary);
  font-size: 12px;
  padding: 2px 16px 6px;
}

.calc-row {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 14px 16px;
  flex-wrap: nowrap;
}

.calc-row .op {
  color: var(--text-secondary);
}

.calc-row .num-input {
  width: 96px;
  padding: 6px 6px;
  text-align: center;
  font-weight: 700;
}

.calc-row .result {
  margin-left: auto;
  font-weight: 700;
  white-space: nowrap;
}

.segmented {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
}

.segmented button {
  flex: 1;
  padding: 10px 0;
  border-radius: 8px;
  border: none;
  background: var(--surface-2);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
}

.segmented button.active {
  background: var(--accent);
  color: #ffffff;
}

.segmented-inline {
  display: flex;
  gap: 6px;
}

.segmented-inline button {
  padding: 6px 10px;
  border-radius: 8px;
  border: none;
  background: var(--surface-2);
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.segmented-inline button.active {
  background: var(--accent);
  color: #ffffff;
}

.link-row {
  display: block;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  text-decoration: none;
  font-size: 16px;
}

.link-row:last-child { border-bottom: none; }

.link-row:active { background: var(--surface-2); }

.subtabbar {
  display: flex;
  overflow-x: auto;
  scrollbar-width: none;
  gap: 2px;
  padding: 12px 10px 0;
  border-bottom: 1px solid var(--border);
}

.subtabbar::-webkit-scrollbar { display: none; }

.subtab {
  flex: 0 0 auto;
  padding: 8px 14px;
  border: none;
  background: none;
  border-radius: 8px 8px 0 0;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
}

.subtab.active {
  color: var(--accent);
  background: var(--surface);
  border-bottom: 2px solid var(--accent);
}

.color-swatches {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 12px 16px;
}

.swatch {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
}

.swatch.selected {
  border-color: var(--text);
}

select.pill-select {
  border: none;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  font-weight: 600;
  font-size: 14px;
  padding: 6px 10px;
  border-radius: 8px;
}

.date-picker-input {
  width: 100%;
  padding: 8px;
  font-size: 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
}

.date-result {
  border-radius: 12px;
  padding: 16px;
  background: color-mix(in srgb, var(--accent) 65%, var(--surface));
  color: #ffffff;
  margin-bottom: 16px;
  text-align: center;
}

.date-result .day {
  display: block;
  font-size: 15px;
  font-weight: 600;
  opacity: 0.9;
  margin-bottom: 4px;
}

.date-result .date {
  display: block;
  font-size: 24px;
  font-weight: 700;
}

.formula-note {
  font-size: 12px;
  color: var(--text-secondary);
  text-align: center;
  padding: 4px 24px 8px;
  margin: 0;
}

.disclaimer {
  font-size: 11px;
  color: var(--text-secondary);
  text-align: center;
  padding: 24px 24px 8px;
  line-height: 1.5;
}