/* ---------- Design tokens ---------- */

:root {
  color-scheme: light dark;

  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --bg: #f2f5fb;
  --glow: #dfe6ff;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #5b6b84;
  --border: #d9e1ef;
  --chip: #f7f9fd;

  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-soft: #eef1ff;
  --on-accent: #ffffff;

  --danger: #dc2626;
  --danger-soft: #fef2f2;
  --on-danger: #ffffff;

  --warn-text: #92400e;
  --warn-soft: #fffbeb;
  --warn-border: #fde68a;

  --shadow: 0 18px 40px -24px rgba(15, 23, 42, 0.45);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #080d19;
    --glow: #121b33;
    --card: #0f1729;
    --text: #e8eefb;
    --muted: #94a3b8;
    --border: #22304d;
    --chip: #152037;

    --accent: #6366f1;
    --accent-hover: #818cf8;
    --accent-soft: #1b2544;
    --on-accent: #ffffff;

    --danger: #f87171;
    --danger-soft: #2a1218;
    --on-danger: #2a0b0b;

    --warn-text: #fcd34d;
    --warn-soft: #241d0b;
    --warn-border: #4d3c12;

    --shadow: 0 18px 40px -24px rgba(0, 0, 0, 0.8);
  }
}

/* ---------- Base ---------- */

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--sans);
  line-height: 1.5;
  color: var(--text);
  background:
    radial-gradient(1000px 520px at 12% -12%, var(--glow), transparent 62%),
    var(--bg);
  -webkit-font-smoothing: antialiased;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.app {
  max-width: 760px;
  margin: 0 auto;
  padding: 48px 20px 64px;
}

/* ---------- Hero ---------- */

.eyebrow {
  margin: 0 0 10px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
}

.hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.8rem, 4.5vw, 2.6rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.hero .sub {
  max-width: 56ch;
  margin: 0 0 28px;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- Cards and fields ---------- */

.card {
  padding: 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.card + .card {
  margin-top: 20px;
}

.field {
  min-inline-size: 0;
  margin: 0 0 20px;
  padding: 0;
  border: 0;
}

.label-row {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 12px;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 8px;
}

label,
legend {
  font-weight: 600;
}

legend {
  padding: 0;
  margin-bottom: 8px;
}

.hint {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--muted);
}

.prefix-row {
  display: flex;
  gap: 10px;
}

input[type="text"] {
  flex: 1;
  min-width: 0;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 1.05rem;
  letter-spacing: 0.08em;
  color: var(--text);
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 12px;
}

input[type="text"]:focus {
  border-color: var(--accent);
}

.help {
  margin: 8px 0 0;
  font-size: 0.83rem;
  color: var(--muted);
}

.help.over {
  color: var(--danger);
}

/* ---------- Buttons ---------- */

.btn {
  padding: 11px 16px;
  font: inherit;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 11px;
  transition:
    background 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease,
    transform 0.15s ease;
}

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

.btn:active {
  transform: translateY(0);
}

.btn.primary {
  color: var(--on-accent);
  background: var(--accent);
  box-shadow: 0 10px 20px -12px var(--accent);
}

.btn.primary:hover {
  background: var(--accent-hover);
}

.btn.primary:disabled {
  cursor: progress;
  opacity: 0.65;
  transform: none;
}

.btn.ghost {
  border-color: var(--border);
}

.btn.ghost:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.btn.small {
  padding: 8px 12px;
  font-size: 0.85rem;
  background: var(--chip);
  border-color: var(--border);
  border-radius: 9px;
}

.btn.small:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.btn.small:disabled {
  cursor: not-allowed;
  opacity: 0.5;
  transform: none;
}

.btn.link {
  padding: 6px 0 0;
  font-size: 0.85rem;
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.btn.link:hover {
  color: var(--danger);
  transform: none;
}

/* ---------- Digit chips ---------- */

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

.chip {
  min-width: 48px;
  padding: 10px 0;
  font: inherit;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  cursor: pointer;
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 11px;
  transition:
    background 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease,
    transform 0.15s ease;
}

.chip:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.chip[aria-pressed="true"] {
  color: var(--on-accent);
  background: var(--accent);
  border-color: var(--accent);
}

#forbidden-chips .chip[aria-pressed="true"] {
  color: var(--on-danger);
  background: var(--danger);
  border-color: var(--danger);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- Messages ---------- */

.warning,
.error {
  margin: 16px 0 0;
  padding: 11px 14px;
  font-size: 0.88rem;
  line-height: 1.5;
  border-radius: 11px;
}

.warning {
  color: var(--warn-text);
  background: var(--warn-soft);
  border: 1px solid var(--warn-border);
}

.error {
  color: var(--danger);
  background: var(--danger-soft);
  border: 1px solid var(--danger);
}

/* ---------- Results ---------- */

.results-head {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.results-head h2 {
  margin: 0;
  font-size: 1.15rem;
}

.result-actions {
  display: flex;
  gap: 8px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 10px;
  margin-bottom: 18px;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 10px 12px;
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.stat-value {
  font-size: 1.05rem;
  font-variant-numeric: tabular-nums;
}

.matches {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(126px, 1fr));
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.matches li {
  padding: 8px 10px;
  font-family: var(--mono);
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
  text-align: center;
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 9px;
}

.matches li:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.note {
  margin: 14px 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.empty {
  margin: 0;
  padding: 22px;
  color: var(--muted);
  text-align: center;
  background: var(--chip);
  border: 1px dashed var(--border);
  border-radius: 12px;
}

/* ---------- Footer ---------- */

.foot {
  margin-top: 22px;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--muted);
  text-align: center;
}

.noscript {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 20px 40px;
  color: #dc2626;
  text-align: center;
}

/* ---------- Small screens ---------- */

@media (max-width: 520px) {
  .app {
    padding-top: 32px;
  }

  .card {
    padding: 18px;
    border-radius: 16px;
  }

  .prefix-row {
    flex-direction: column;
  }

  .prefix-row .btn {
    width: 100%;
  }

  .matches {
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
  }
}