/* ─────────────────────────────────────────────────────────────────────────
   TracksideRacing.AI — marketing site stylesheet.
   Single file, no preprocessor, no Tailwind. Token spec lives in
   ../../docs/design-system.md and is mirrored in tsr-fe/src/styles/globals.css.
   ───────────────────────────────────────────────────────────────────────── */

/* Light theme (default) */
:root {
  --bg-primary:       #fbfbfa;
  --bg-surface:       #ffffff;
  --bg-elevated:      #f4f4f2;

  --border:           #e6e5e0;
  --border-strong:    #d6d5cf;

  --accent-primary:   #0f6b3c;
  --accent-hover:     #0a4f2a;
  --accent-secondary: #1d4ed8;
  --accent-on-accent: #ffffff;

  --text-primary:     #1a1a1a;
  --text-secondary:   #5b5b5b;
  --text-muted:       #8a8a8a;
  --text-tag:         #2a2a2a;

  --button-bg:        #0f0f0f;
  --button-text:      #ffffff;

  --success:          #10b981;
  --warning:          #f59e0b;
  --danger:           #ef4444;

  color-scheme: light;
}

/* Dark theme */
:root.dark, :root[data-theme="dark"] {
  --bg-primary:       #0d1117;
  --bg-surface:       #161b22;
  --bg-elevated:      #1c232c;

  --border:           #272f3a;
  --border-strong:    #343e4c;

  --accent-primary:   #3fb950;
  --accent-hover:     #2da944;
  --accent-secondary: #38bdf8;
  --accent-on-accent: #04140b;

  --text-primary:     #f0f3f6;
  --text-secondary:   #9aa4b2;
  --text-muted:       #6a7484;
  --text-tag:         #cdd5e0;

  --button-bg:        #f0f3f6;
  --button-text:      #0d1117;

  color-scheme: dark;
}

/* ─────────────────────────────── Reset / base ─────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

html {
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: Manrope, Inter, system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: -0.011em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "ss01", "cv11";
  font-variant-numeric: tabular-nums;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

img { max-width: 100%; height: auto; display: block; }

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

button { font: inherit; cursor: pointer; }

h1, h2, h3, h4 {
  margin: 0;
  color: var(--text-primary);
  font-weight: 600;
}
h1 { letter-spacing: -0.035em; }
h2 { letter-spacing: -0.030em; }
h3 { letter-spacing: -0.015em; }

p { margin: 0; }

ul { margin: 0; padding: 0; list-style: none; }

/* Scrollbars */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Visually hidden — accessible */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}

/* ─────────────────────────────── Layout helpers ─────────────────────────────── */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding-left: 1rem;
  padding-right: 1rem;
}
@media (min-width: 640px) {
  .container { padding-left: 1.5rem; padding-right: 1.5rem; }
}
@media (min-width: 1024px) {
  .container { padding-left: 2rem; padding-right: 2rem; }
}

.section { padding: 3rem 0; }
@media (min-width: 640px) { .section { padding: 4rem 0; } }
.section--tight-top { padding-top: 0; }

.prose-narrow { max-width: 48rem; }

/* ─────────────────────────────── Header ─────────────────────────────── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--bg-primary) 85%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.site-header__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
@media (min-width: 640px) { .site-header__inner { padding: 0 1.5rem; } }
@media (min-width: 1024px) { .site-header__inner { padding: 0 2rem; } }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--text-primary);
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand__logo {
  width: 32px;
  height: 32px;
  object-fit: contain;
}
:root.dark .brand__logo,
:root[data-theme="dark"] .brand__logo {
  filter: invert(1) brightness(0.92) hue-rotate(80deg) saturate(0.4);
}
.brand__text {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.brand__accent { color: var(--accent-primary); }

.nav-primary {
  display: none;
  align-items: center;
  gap: 1.5rem;
}
@media (min-width: 768px) {
  .nav-primary { display: inline-flex; }
}
.nav-primary a {
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-decoration: none;
  transition: color 150ms ease;
}
.nav-primary a:hover { color: var(--text-primary); }
.nav-primary a.is-active { color: var(--accent-primary); }

.nav-actions {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  border-radius: 6px;
}
.menu-toggle:hover { color: var(--text-primary); }
@media (min-width: 768px) { .menu-toggle { display: none; } }
.menu-toggle svg { width: 20px; height: 20px; }

.nav-mobile {
  display: none;
  border-top: 1px solid var(--border);
  background: var(--bg-surface);
  padding: 0.5rem 1rem;
}
@media (min-width: 768px) { .nav-mobile { display: none !important; } }
.nav-mobile.is-open { display: block; }
.nav-mobile a {
  display: block;
  padding: 0.5rem 0.75rem;
  margin: 0.125rem 0;
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-decoration: none;
}
.nav-mobile a:hover { background: var(--bg-elevated); color: var(--text-primary); }
.nav-mobile a.is-active {
  background: color-mix(in srgb, var(--accent-primary) 12%, transparent);
  color: var(--accent-primary);
}

/* ─────────────────────────────── Theme toggle ─────────────────────────────── */

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 9999px;
  padding: 3px;
}
.theme-toggle__btn {
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 500;
  text-transform: capitalize;
  padding: 4px 12px;
  border-radius: 9999px;
  transition: color 150ms ease, background 150ms ease, border-color 150ms ease;
}
.theme-toggle__btn:hover { color: var(--text-primary); }
.theme-toggle__btn[aria-pressed="true"] {
  background: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border);
}

/* ─────────────────────────────── Buttons ─────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn--primary {
  background: var(--accent-primary);
  color: var(--accent-on-accent);
}
.btn--primary:hover:not(:disabled) { background: var(--accent-hover); }

.btn--secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border);
}
.btn--secondary:hover { border-color: var(--border-strong); }

.btn--block { width: 100%; }

/* ─────────────────────────────── Forms ─────────────────────────────── */

.field {
  display: block;
  width: 100%;
}
.field + .field { margin-top: 0.75rem; }

.field__label {
  display: block;
  color: var(--text-secondary);
  font-size: 0.75rem;
  margin-bottom: 0.25rem;
}

.input {
  display: block;
  width: 100%;
  padding: 0.5rem 0.75rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font: inherit;
  font-size: 0.875rem;
  border-radius: 6px;
  transition: border-color 150ms ease, box-shadow 150ms ease;
}
.input::placeholder { color: var(--text-muted); }
.input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-primary) 30%, transparent);
}

.checkbox-row {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  cursor: pointer;
  margin-top: 0.75rem;
}
.checkbox-row input[type="checkbox"] {
  margin-top: 4px;
  accent-color: var(--accent-primary);
  flex-shrink: 0;
}
.checkbox-row__label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ─────────────────────────────── Eyebrow / hero ─────────────────────────────── */

.eyebrow {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent-primary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.75rem;
}

.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 1rem 3rem;
}
@media (min-width: 640px) {
  .hero { padding: 6rem 1.5rem 4rem; }
}
@media (min-width: 1024px) {
  .hero { padding-left: 2rem; padding-right: 2rem; }
}
.hero__inner { max-width: 48rem; }
.hero__title {
  font-size: clamp(2.25rem, 4vw + 1rem, 3.5rem);
  line-height: 1.05;
  font-weight: 700;
  letter-spacing: -0.035em;
}
.hero__subtitle {
  margin-top: 1.5rem;
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.hero__actions {
  margin-top: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ─────────────────────────────── Cards / grid ─────────────────────────────── */

.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
}
.card--feature { transition: border-color 150ms ease; }
.card--feature:hover {
  border-color: color-mix(in srgb, var(--accent-primary) 40%, var(--border));
}
.card__h { font-size: 1rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.5rem; }
.card__body { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.6; }

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: color-mix(in srgb, var(--accent-primary) 12%, transparent);
  color: var(--accent-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}
.feature-icon svg { width: 20px; height: 20px; }

.grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 1fr;
}
.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }
@media (min-width: 640px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* ─────────────────────────────── Pricing ─────────────────────────────── */

.tier {
  display: flex;
  flex-direction: column;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  position: relative;
  transition: border-color 150ms ease;
}
.tier--highlighted {
  border-color: var(--accent-primary);
  box-shadow: 0 8px 24px -8px color-mix(in srgb, var(--accent-primary) 25%, transparent);
}
.tier__badge {
  position: absolute;
  top: -12px;
  left: 1.5rem;
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  background: var(--accent-primary);
  color: var(--accent-on-accent);
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 6px;
}
.tier__name { font-size: 1.125rem; font-weight: 600; color: var(--text-primary); }
.tier__tagline { margin-top: 0.25rem; font-size: 0.875rem; color: var(--text-muted); }
.tier__price {
  margin-top: 1rem;
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}
.tier__price-value {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.03em;
}
.tier__price-cadence { font-size: 0.875rem; color: var(--text-muted); }
.tier__features {
  margin-top: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.tier__features li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.tier__features svg {
  width: 16px;
  height: 16px;
  margin-top: 3px;
  color: var(--success);
  flex-shrink: 0;
}
.tier__cta { margin-top: 1.5rem; }

/* ─────────────────────────────── FAQ accordion (native <details>) ─────────────────────────────── */

.faq {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}
.faq details + details { border-top: 1px solid var(--border); }
.faq summary {
  list-style: none;
  cursor: pointer;
  padding: 1rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: color 150ms ease;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary:hover { color: var(--accent-primary); }
.faq summary::after {
  content: "";
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--text-muted);
  border-bottom: 2px solid var(--text-muted);
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform 200ms ease;
  flex-shrink: 0;
}
.faq details[open] summary::after {
  transform: rotate(-135deg) translate(-2px, -2px);
}
.faq__answer {
  padding: 0 1.5rem 1rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─────────────────────────────── Legal pages (long-form prose) ─────────────────────────────── */

.legal h1 {
  font-size: clamp(1.875rem, 2.5vw + 1rem, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.035em;
}
.legal__updated {
  margin-top: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}
.legal__body {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.65;
}
.legal__body h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}
.legal__body p + p { margin-top: 0.75rem; }
.legal__body ul {
  list-style: disc;
  padding-left: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.legal__body section { display: block; }
.legal__footer-note {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ─────────────────────────────── Footer ─────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-surface);
  padding: 2.5rem 0;
  margin-top: 4rem;
}
.site-footer__grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr 1fr;
}
@media (min-width: 768px) {
  .site-footer__grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
}
.site-footer__brand-col { grid-column: 1 / -1; }
@media (min-width: 768px) {
  .site-footer__brand-col { grid-column: auto; }
}
.site-footer__tagline {
  margin-top: 0.75rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}
.site-footer h3 {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}
.site-footer ul { display: flex; flex-direction: column; gap: 0.5rem; }
.site-footer ul a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
}
.site-footer ul a:hover { color: var(--text-primary); }

.site-footer__bottom {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}
@media (min-width: 640px) {
  .site-footer__bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

/* ─────────────────────────────── Landing (Coming Soon) page ─────────────────────────────── */

.landing-page {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 1rem;
}
.landing-card {
  width: 100%;
  max-width: 32rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.landing-logo { width: 160px; height: 160px; margin: 0 auto; object-fit: contain; }
:root.dark .landing-logo,
:root[data-theme="dark"] .landing-logo {
  filter: invert(1) brightness(0.92) hue-rotate(80deg) saturate(0.4);
}
.landing-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.035em;
}
.landing-tagline {
  margin-top: 0.5rem;
  font-size: 1.125rem;
  color: var(--text-secondary);
}
.landing-form-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg-surface);
  padding: 2rem;
  text-align: left;
}
.landing-form-card h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  text-align: center;
}
.landing-form-card__intro {
  margin-top: 0.75rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.6;
}
.landing-form { margin-top: 1.25rem; }
.form-status { margin-top: 0.75rem; font-size: 0.875rem; }
.form-status--success { color: var(--success); font-weight: 500; }
.form-status--error { color: var(--danger); font-size: 0.75rem; }

.landing-copy {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ─────────────────────────────── Contact page ─────────────────────────────── */

.contact-grid {
  display: grid;
  gap: 2.5rem;
  grid-template-columns: 1fr;
}
@media (min-width: 1024px) {
  .contact-grid { grid-template-columns: 1fr 1fr; align-items: start; }
}
.contact-prose {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
}
.contact-prose h2 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}
.contact-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
@media (min-width: 640px) { .contact-card { padding: 2rem; } }
.contact-card__label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.contact-card__email {
  display: block;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--accent-primary);
  word-break: break-all;
}
.contact-card__email:hover { text-decoration: underline; }
.contact-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.contact-card__note {
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ─────────────────────────────── Blog ─────────────────────────────── */

.blog-empty {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 3rem 1.5rem;
  text-align: center;
}
.blog-empty h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}
.blog-empty p {
  margin-top: 0.5rem;
  max-width: 28rem;
  margin-left: auto;
  margin-right: auto;
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.blog-empty .btn { margin-top: 1.5rem; }

/* ─────────────────────────────── Utilities ─────────────────────────────── */

.text-center { text-align: center; }
.muted { color: var(--text-muted); }
.small { font-size: 0.875rem; }
.tiny { font-size: 0.75rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.mt-12 { margin-top: 3rem; }
.mt-16 { margin-top: 4rem; }