/* tireandwheelcalc.com — dark instrument-panel design system.
   See DESIGN.md before changing colors, type, or spacing rules. */

:root {
  --bg: #0b0e11;
  --bg-panel: #12161b;
  --bg-panel-raised: #171c22;
  --border: #262d35;
  --border-strong: #333c46;

  --text: #e8ecef;
  --text-dim: #93a1ad;
  --text-faint: #5c6773;

  --accent: #ff8a3d;
  --accent-dim: #cc6a1f;
  --good: #3ddc84;
  --warn: #ffcf4d;
  --danger: #ff5c5c;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "IBM Plex Mono", "Cascadia Mono", Menlo, Consolas, monospace;

  --radius: 10px;
  --tap-min: 44px;
}

* { box-sizing: border-box; }

html { background: var(--bg); }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin: 0 0 0.5em;
}

h1 { font-size: clamp(1.6rem, 5vw, 2.4rem); }
h2 { font-size: clamp(1.25rem, 3.5vw, 1.6rem); }
h3 { font-size: 1.1rem; }

p { margin: 0 0 1em; color: var(--text-dim); }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Figures — every number, unit, and spec string is monospace. */
.figure, .mono, code, kbd, output, input {
  font-family: var(--font-mono);
}

.wrap {
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  padding: 0 20px;
}

.wrap-wide {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Header / nav ----------------------------------------------------- */

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg-panel);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.site-logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  white-space: nowrap;
}

.site-logo .logo-accent { color: var(--accent); }

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  font-size: 0.9rem;
}

.site-nav a {
  color: var(--text-dim);
  padding: 10px 12px;
  min-height: var(--tap-min);
  display: flex;
  align-items: center;
  border-radius: 6px;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--text);
  background: var(--bg-panel-raised);
  text-decoration: none;
}

/* --- Page structure ----------------------------------------------------- */

main { padding: 32px 0 64px; }

.page-head { margin-bottom: 32px; }

.lead {
  font-size: 1.05rem;
  color: var(--text-dim);
  max-width: 60ch;
}

section { margin-bottom: 40px; }

/* --- Panels / cards ----------------------------------------------------- */

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.panel-raised {
  background: var(--bg-panel-raised);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 24px;
}

.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 640px) {
  .card-grid.cols-2 { grid-template-columns: 1fr 1fr; }
  .card-grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
}

.tool-card {
  display: block;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  color: var(--text);
}

.tool-card:hover {
  border-color: var(--accent-dim);
  text-decoration: none;
}

.tool-card h3 { margin-bottom: 6px; }
.tool-card p { margin: 0; font-size: 0.92rem; }

/* --- Forms (calculator input shell) ------------------------------------- */

.field-group { margin-bottom: 20px; }

.field-group legend,
.field-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 560px) {
  .field-row.cols-3 { grid-template-columns: repeat(3, 1fr); }
  .field-row.cols-2 { grid-template-columns: repeat(2, 1fr); }
}

label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 6px;
}

input[type="text"],
input[type="number"] {
  width: 100%;
  min-height: var(--tap-min);
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  color: var(--text);
  padding: 10px 12px;
  font-size: 1rem;
}

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

.field-group.has-error input {
  border-color: var(--danger);
}

.field-error {
  margin: 6px 0 0;
  font-size: 0.8rem;
  color: var(--danger);
}

.field-error:empty {
  display: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--tap-min);
  padding: 12px 24px;
  border-radius: 8px;
  border: none;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: #17110a;
}

.btn-primary:hover { background: #ffa15f; }

.btn-block { width: 100%; }

/* --- Result block -------------------------------------------------------- */

.result-diagram {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 20px;
}

.result-diagram svg { display: block; width: 100%; height: auto; }

.speedo-line {
  font-size: clamp(1.3rem, 5vw, 1.8rem);
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent);
  margin: 0 0 8px;
}

.speedo-line-sub {
  font-size: 0.95rem;
  font-family: var(--font-mono);
  color: var(--text-dim);
  margin: 0 0 24px;
}

.result-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 20px;
}

.result-stat {
  background: var(--bg-panel);
  padding: 14px 16px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.result-stat .stat-label {
  color: var(--text-dim);
  font-size: 0.9rem;
}

.result-stat .stat-value {
  font-family: var(--font-mono);
  font-weight: 600;
}

.stat-value.good { color: var(--good); }
.stat-value.warn { color: var(--warn); }
.stat-value.danger { color: var(--danger); }

/* --- Affiliate CTA slot ---------------------------------------------------
   Lives inside the result block, next to the numbers it corresponds to.
   href is a plain untracked retailer search URL until an affiliate
   program is approved — see DESIGN.md. */

.affiliate-slot {
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.affiliate-slot .affiliate-copy { font-size: 0.9rem; color: var(--text-dim); }
.affiliate-slot .affiliate-size { color: var(--text); font-family: var(--font-mono); }

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

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 40px 0 24px;
  margin-top: 40px;
}

.footer-cols {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 28px;
}

@media (min-width: 640px) {
  .footer-cols { grid-template-columns: 2fr 1fr 1fr; }
}

.footer-brand {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.footer-cols h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-faint);
  margin-bottom: 10px;
}

.footer-cols ul { list-style: none; margin: 0; padding: 0; }
.footer-cols li { margin-bottom: 8px; }
.footer-cols a { color: var(--text-dim); }

.footer-legal {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  font-size: 0.85rem;
  color: var(--text-faint);
}

.footer-legal p { color: var(--text-faint); font-size: 0.85rem; margin-bottom: 8px; }
.footer-links a { color: var(--text-dim); }

.disclaimer { font-size: 0.85rem; color: var(--text-faint); }

.badge-pending {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-faint);
  border: 1px dashed var(--border-strong);
  border-radius: 6px;
  padding: 2px 8px;
}