/* ---------- Design tokens ---------- */
:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #eef1f7;
  --border: #dfe3ec;
  --text: #1a1f2b;
  --text-muted: #5b6472;
  --primary: #2563eb;
  --primary-contrast: #ffffff;
  --up: #059669;
  --down: #dc2626;
  --focus: #2563eb;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 8px 24px rgba(16, 24, 40, .06);
  --radius: 14px;
  --radius-sm: 9px;
}

:root[data-theme="dark"],
:root[data-theme="auto"] {
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] {
    --bg: #0e1116;
    --surface: #171b22;
    --surface-2: #1f242d;
    --border: #2b313c;
    --text: #e7ebf3;
    --text-muted: #9aa4b2;
    --primary: #4f8cff;
    --primary-contrast: #0b0f16;
    --up: #34d399;
    --down: #f87171;
    --focus: #4f8cff;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 12px 32px rgba(0, 0, 0, .35);
  }
}

:root[data-theme="dark"] {
  --bg: #0e1116;
  --surface: #171b22;
  --surface-2: #1f242d;
  --border: #2b313c;
  --text: #e7ebf3;
  --text-muted: #9aa4b2;
  --primary: #4f8cff;
  --primary-contrast: #0b0f16;
  --up: #34d399;
  --down: #f87171;
  --focus: #4f8cff;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 12px 32px rgba(0, 0, 0, .35);
}

/* ---------- Base ---------- */
* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--surface-2);
  padding: .1em .4em;
  border-radius: 6px;
  font-size: .9em;
}

h1 {
  font-size: 1.25rem;
  margin: 0;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 clamp(12px, 4vw, 24px) 48px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px clamp(12px, 4vw, 24px);
  padding-top: max(12px, env(safe-area-inset-top));
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(8px);
  border-bottom: 1px solid var(--border);
}

.site-header__title {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo {
  font-size: 1.4rem;
}

.lede {
  color: var(--text-muted);
  margin: 20px 0 16px;
  max-width: 62ch;
}

/* ---------- Cards ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.controls {
  padding: clamp(14px, 3vw, 20px);
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  gap: 8px;
}

.field-label,
.field label {
  font-size: .82rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: .01em;
}

.input-row {
  display: flex;
  gap: 8px;
}

input[type="text"] {
  flex: 1;
  min-width: 0;
  font-size: 16px; /* prevents iOS zoom on focus */
  padding: 12px 14px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: border-color .15s, box-shadow .15s;
}

input[type="text"]::placeholder {
  color: var(--text-muted);
  opacity: .7;
}

input[type="text"]:focus-visible,
.btn:focus-visible,
.seg:focus-visible,
.chip:focus-visible,
.icon-btn:focus-visible {
  outline: none;
  border-color: var(--focus);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--focus) 30%, transparent);
}

.hint {
  margin: 0;
  font-size: .8rem;
  color: var(--text-muted);
}

/* ---------- Buttons ---------- */
.btn {
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  padding: 12px 18px;
  white-space: nowrap;
  transition: background .15s, border-color .15s, transform .05s;
}

.btn:active {
  transform: translateY(1px);
}

.btn--primary {
  background: var(--primary);
  color: var(--primary-contrast);
}

.btn--primary:hover {
  background: color-mix(in srgb, var(--primary) 88%, black);
}

.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
  padding: 9px 14px;
}

.btn--ghost:hover {
  background: var(--surface-2);
}

.icon-btn {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.icon-btn:hover {
  background: var(--surface-2);
}

.theme-icon::before {
  content: "🌙";
  font-size: 1.1rem;
}

:root[data-theme="dark"] .theme-icon::before {
  content: "☀️";
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] .theme-icon::before {
    content: "☀️";
  }
}

/* ---------- Example chips ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  font: inherit;
  font-size: .82rem;
  cursor: pointer;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text);
}

.chip:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* ---------- Segmented range control ---------- */
.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 4px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 11px;
  width: fit-content;
  max-width: 100%;
}

.seg {
  font: inherit;
  font-weight: 600;
  font-size: .88rem;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--text-muted);
  padding: 8px 16px;
  border-radius: 8px;
  flex: 1 0 auto;
  transition: background .15s, color .15s;
}

.seg:hover {
  color: var(--text);
}

.seg[aria-pressed="true"] {
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 1px 2px rgba(0, 0, 0, .12);
}

/* ---------- Toggles ---------- */
.field--toggles {
  grid-auto-flow: column;
  justify-content: start;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: .9rem;
  font-weight: 500;
  color: var(--text);
  user-select: none;
}

.toggle input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* ---------- Banner ---------- */
.banner[hidden] {
  /* Must win over the .banner--loading display rule below. */
  display: none;
}

.banner {
  margin-top: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  font-size: .92rem;
}

.banner--error {
  background: color-mix(in srgb, var(--down) 12%, var(--surface));
  border-color: color-mix(in srgb, var(--down) 45%, var(--border));
  color: var(--text);
}

.banner--info {
  background: color-mix(in srgb, var(--primary) 12%, var(--surface));
  border-color: color-mix(in srgb, var(--primary) 40%, var(--border));
}

.banner--loading {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--surface);
}

.spinner {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid color-mix(in srgb, var(--primary) 35%, transparent);
  border-top-color: var(--primary);
  animation: spin .7s linear infinite;
  flex: none;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .spinner {
    animation-duration: 2s;
  }
}

/* ---------- Chart ---------- */
.chart-card {
  margin-top: 16px;
  padding: 10px;
  position: relative;
}

.chart-caption {
  margin: 4px 6px 8px;
  font-size: .82rem;
  color: var(--text-muted);
}

.chart {
  width: 100%;
  height: clamp(320px, 56vh, 560px);
}

.chart-empty {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--text-muted);
  padding: 24px;
  pointer-events: none;
}

/* ---------- Summary cards ---------- */
.summary {
  margin-top: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
}

.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left-width: 4px;
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  box-shadow: var(--shadow);
}

.stat__name {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: .95rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.stat__swatch {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  flex: none;
}

.stat__value {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 6px;
  letter-spacing: -.01em;
}

.stat__change {
  font-size: .95rem;
  font-weight: 600;
  margin-top: 2px;
}

.stat__meta {
  font-size: .78rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.up {
  color: var(--up);
}

.down {
  color: var(--down);
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 28px;
  color: var(--text-muted);
  font-size: .8rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 560px) {
  .input-row {
    flex-wrap: wrap;
  }

  .btn--primary {
    flex: 1 1 100%;
  }

  .segmented {
    width: 100%;
  }

  .field--toggles {
    grid-auto-flow: row;
    gap: 14px;
  }
}