/* =============================================================================
   Overdrive Exhausts — site.css
   One stylesheet for the whole store. Dark is the default brand look; a
   prefers-color-scheme: light block at the bottom re-maps the tokens.
   Sections:
     1. Tokens          5. Buttons & forms      9. Cart
     2. Base            6. Home                10. Success / content pages
     3. Header & nav    7. Shop                11. Utilities
     4. Footer          8. Product             12. Light mode
   ============================================================================= */

/* ---------- 1. Tokens ------------------------------------------------------- */
:root {
  color-scheme: dark;

  /* colour */
  --bg:            #0b0c0f;
  --bg-elevated:   #111318;
  --surface:       #15171c;
  --surface-2:     #1d2027;
  --surface-3:     #262a33;
  --border:        #2a2e37;
  --border-strong: #3a3f4a;
  --text:          #f2f3f5;
  --text-muted:    #a2a7b3;
  --text-faint:    #6f7481;
  --accent:        #ff5a1f;      /* exhaust glow — CTAs & highlights only */
  --accent-hover:  #ff7a47;
  --accent-text:   #ff6a35;      /* accent used as text on dark surfaces */
  --on-accent:     #0b0c0f;
  --info:          #5aa9ff;      /* titanium blue — informational accents */
  --info-text:     #7dbcff;
  --success:       #41c98a;
  --danger:        #ff6b6b;
  --danger-text:   #ff8080;
  --focus:         #5aa9ff;

  /* header / footer are always dark (brand) */
  --chrome-bg:     #0b0c0f;
  --chrome-border: #22252d;
  --chrome-text:   #f2f3f5;
  --chrome-muted:  #a2a7b3;

  /* type */
  --font-heading: "Barlow Condensed", "Arial Narrow", "Helvetica Neue", Arial, sans-serif;
  --font-body:    "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  /* spacing & layout */
  --space-1: 4px;  --space-2: 8px;  --space-3: 12px; --space-4: 16px;
  --space-5: 24px; --space-6: 32px; --space-7: 48px; --space-8: 64px;
  --space-9: 96px;
  --gutter:    16px;
  --max-width: 1200px;
  --radius-s:  6px;
  --radius:    10px;
  --radius-l:  16px;
  --shadow:    0 10px 30px rgba(0, 0, 0, .45);
  --header-h:  64px;
}

/* ---------- 2. Base --------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;               /* belt-and-braces: never a horizontal page scroll */
  -webkit-font-smoothing: antialiased;
}

main { flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  text-transform: uppercase;
  letter-spacing: -.01em;
  line-height: 1.05;
  margin: 0 0 var(--space-3);
  font-weight: 700;
}
h1 { font-size: clamp(2.4rem, 6vw, 4rem); }
h2 { font-size: clamp(1.9rem, 4vw, 2.6rem); }
h3 { font-size: clamp(1.3rem, 2.5vw, 1.6rem); }
h4 { font-size: 1.15rem; }

p { margin: 0 0 var(--space-4); }
p:last-child { margin-bottom: 0; }

a {
  color: var(--info-text);
  text-decoration: underline;
  text-underline-offset: .15em;
  text-decoration-thickness: 1px;
}
a:hover { color: var(--text); }

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

ul, ol { padding-left: 1.25em; margin: 0 0 var(--space-4); }
li { margin-bottom: var(--space-1); }

hr { border: 0; border-top: 1px solid var(--border); margin: var(--space-6) 0; }

code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9em; }

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 2px;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section { padding: var(--space-8) 0; }
.section--tight { padding: var(--space-6) 0; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-3) var(--space-5);
  margin-bottom: var(--space-5);
}
.section-head h2 { margin: 0; }
.section-head p  { margin: 0; color: var(--text-muted); }

.eyebrow {
  display: inline-block;
  font-family: var(--font-heading);
  text-transform: uppercase;
  letter-spacing: .14em;
  font-size: .85rem;
  font-weight: 600;
  color: var(--accent-text);
  margin-bottom: var(--space-2);
}

.muted { color: var(--text-muted); }
.small { font-size: .875rem; }

.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -100px;
  background: var(--accent);
  color: var(--on-accent);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-s);
  z-index: 100;
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus { top: var(--space-4); }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* ---------- 3. Header & nav ------------------------------------------------ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--chrome-bg);
  color: var(--chrome-text);
  border-bottom: 1px solid var(--chrome-border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
}
.brand img { height: 30px; width: auto; }

/* The nav toggle is a hidden checkbox so the mobile menu works with no JS. */
.nav-toggle-input { position: absolute; opacity: 0; width: 1px; height: 1px; pointer-events: none; }
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;
  border: 1px solid var(--chrome-border);
  border-radius: var(--radius-s);
  background: transparent;
  color: var(--chrome-text);
  cursor: pointer;
}
.nav-toggle-input:focus-visible + .nav-toggle { outline: 2px solid var(--focus); outline-offset: 2px; }
.nav-toggle .icon-close { display: none; }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  margin-left: auto; /* nav + cart link sit at the right edge on desktop */
}
.site-nav a {
  color: var(--chrome-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: .95rem;
  padding: var(--space-2) 0;
  border-bottom: 2px solid transparent;
  transition: color .15s;
}
.site-nav a:hover { color: var(--chrome-text); }
.site-nav a[aria-current="page"] { color: var(--chrome-text); border-bottom-color: var(--accent); }

.cart-link {
  display: inline-flex !important;
  align-items: center;
  gap: var(--space-2);
  color: var(--chrome-text) !important;
}
.cart-link svg { width: 22px; height: 22px; }
.cart-badge {
  min-width: 20px; height: 20px;
  padding: 0 6px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--on-accent);
  font-size: .75rem;
  font-weight: 700;
  line-height: 20px;
  text-align: center;
}
.cart-badge[hidden] { display: none; }

@media (max-width: 767px) {
  /* Row order on phones: brand | cart | menu button; the nav itself becomes a dropdown. */
  .cart-link { order: 2; margin-left: auto; }
  .nav-toggle { display: inline-flex; order: 3; }
  .site-nav {
    display: none;
    position: absolute;
    left: 0; right: 0; top: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--chrome-bg);
    border-bottom: 1px solid var(--chrome-border);
    padding: var(--space-2) var(--gutter) var(--space-4);
    box-shadow: var(--shadow);
  }
  .site-nav a {
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--chrome-border);
    font-size: 1.05rem;
  }
  .site-nav a[aria-current="page"] { border-bottom-color: var(--chrome-border); color: var(--accent-text); }
  .nav-toggle-input:checked ~ .site-nav { display: flex; }
  .nav-toggle-input:checked + .nav-toggle .icon-menu  { display: none; }
  .nav-toggle-input:checked + .nav-toggle .icon-close { display: block; }
}

/* ---------- 4. Footer ------------------------------------------------------ */
.site-footer {
  background: var(--chrome-bg);
  color: var(--chrome-muted);
  border-top: 1px solid var(--chrome-border);
  margin-top: var(--space-8);
  font-size: .9rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-6);
  padding: var(--space-7) 0 var(--space-6);
}
.footer-brand img { height: 26px; width: auto; margin-bottom: var(--space-3); }
.footer-brand p { max-width: 42ch; }
.site-footer h4 {
  color: var(--chrome-text);
  font-size: .95rem;
  letter-spacing: .1em;
  margin-bottom: var(--space-3);
}
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: var(--space-2); }
.site-footer a { color: var(--chrome-muted); text-decoration: none; }
.site-footer a:hover { color: var(--chrome-text); text-decoration: underline; }
.footer-ship {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--chrome-text);
  font-weight: 500;
}
.footer-ship svg { width: 18px; height: 18px; color: var(--info); }
.footer-legal {
  border-top: 1px solid var(--chrome-border);
  padding: var(--space-4) 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2) var(--space-5);
  font-size: .8rem;
  color: var(--text-faint);
}
.footer-legal p { margin: 0; max-width: 70ch; }

@media (max-width: 767px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

/* ---------- 5. Buttons & forms -------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 44px;
  padding: 0 var(--space-5);
  border-radius: var(--radius-s);
  border: 1px solid transparent;
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: background .15s, border-color .15s, color .15s, transform .05s;
}
.btn:active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .55; cursor: not-allowed; transform: none; }

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

.btn--secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--border-strong);
}
.btn--secondary:hover:not(:disabled) { border-color: var(--text); color: var(--text); }

.btn--ghost { background: transparent; color: var(--text-muted); }
.btn--ghost:hover:not(:disabled) { color: var(--text); }

.btn--block { width: 100%; }
.btn--sm { min-height: 36px; padding: 0 var(--space-4); font-size: .95rem; }

label { font-weight: 500; font-size: .9rem; }

input[type="text"], input[type="search"], input[type="email"], input[type="number"], select, textarea {
  width: 100%;
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-s);
  font: inherit;
  font-size: 1rem;
}
input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 0;
  border-color: var(--focus);
}
input::placeholder { color: var(--text-faint); }
select { cursor: pointer; }

.field { display: flex; flex-direction: column; gap: var(--space-2); margin-bottom: var(--space-4); }

.search-form {
  display: flex;
  gap: var(--space-2);
  width: 100%;
  max-width: 560px;
}
.search-form input { flex: 1 1 auto; min-width: 0; }

/* Quantity stepper — shared by product and cart pages */
.qty {
  display: inline-flex;
  align-items: stretch;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-s);
  overflow: hidden;
  background: var(--surface);
}
.qty button {
  width: 40px;
  border: 0;
  background: transparent;
  color: var(--text);
  font-size: 1.2rem;
  cursor: pointer;
}
.qty button:hover:not(:disabled) { background: var(--surface-3); }
.qty button:disabled { color: var(--text-faint); cursor: not-allowed; }
.qty input {
  width: 48px;
  min-height: 42px;
  border: 0;
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-radius: 0;
  text-align: center;
  padding: 0;
  -moz-appearance: textfield;
  appearance: textfield;
}
.qty input::-webkit-outer-spin-button, .qty input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.qty input:focus-visible { outline-offset: -2px; }

/* Notices */
.notice {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-s);
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: .95rem;
}
.notice--info    { border-color: rgba(90, 169, 255, .4); }
.notice--warn    { border-color: rgba(255, 90, 31, .5); }
.notice--danger  { border-color: rgba(255, 107, 107, .5); color: var(--danger-text); }
.notice--success { border-color: rgba(65, 201, 138, .5); }
.notice[hidden]  { display: none; }

/* ---------- 6. Home -------------------------------------------------------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: var(--space-9) 0 var(--space-8);
  background:
    radial-gradient(60% 80% at 85% 20%, rgba(255, 90, 31, .18), transparent 60%),
    radial-gradient(40% 60% at 10% 90%, rgba(90, 169, 255, .10), transparent 60%),
    var(--bg);
  border-bottom: 1px solid var(--border);
}
.hero .container {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: var(--space-7);
  align-items: center;
}
.hero h1 { font-size: clamp(2.8rem, 7vw, 5rem); margin-bottom: var(--space-4); }
.hero h1 em { font-style: normal; color: var(--accent-text); }
.hero .lede { font-size: 1.15rem; color: var(--text-muted); max-width: 52ch; margin-bottom: var(--space-5); }
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-bottom: var(--space-6); }
.hero-art img { width: 100%; filter: drop-shadow(0 30px 40px rgba(0, 0, 0, .5)); }
.hero-search label { display: block; margin-bottom: var(--space-2); color: var(--text-muted); }

@media (max-width: 899px) {
  .hero { padding: var(--space-7) 0; }
  .hero .container { grid-template-columns: 1fr; }
  .hero-art { order: -1; max-width: 520px; }
}

.make-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-3);
}
.make-tile {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 120px;
  padding: var(--space-4) var(--space-4);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  text-decoration: none;
  transition: border-color .15s, transform .15s, background .15s;
}
.make-tile:hover { border-color: var(--accent); transform: translateY(-2px); color: var(--text); }
.make-tile__name {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 700;
  text-transform: uppercase;
  line-height: 1;
}
.make-tile__count { font-size: .85rem; color: var(--text-muted); }
@media (max-width: 899px) { .make-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
@media (max-width: 599px) { .make-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .make-tile__name { font-size: 1.35rem; } }

.features {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-4);
}
.feature {
  padding: var(--space-5);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.feature svg { width: 32px; height: 32px; color: var(--info); margin-bottom: var(--space-3); }
.feature h3 { font-size: 1.35rem; }
.feature p { color: var(--text-muted); font-size: .95rem; }
@media (max-width: 899px) { .features { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 479px) { .features { grid-template-columns: 1fr; } }

.cta-block {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4) var(--space-6);
  padding: var(--space-6);
  background: linear-gradient(135deg, var(--surface-2), var(--surface));
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
}
.cta-block h2 { margin-bottom: var(--space-2); }
.cta-block p { color: var(--text-muted); max-width: 56ch; }

/* ---------- 7. Shop -------------------------------------------------------- */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-4);
}
.product-card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .15s, transform .15s;
}
.product-card:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.product-card__media {
  aspect-ratio: 16 / 9;
  background: radial-gradient(80% 90% at 50% 100%, var(--surface-3), var(--surface) 80%);
  padding: var(--space-3);
  display: flex;
  align-items: center;
}
.product-card__media img { width: 100%; height: 100%; object-fit: contain; }
.product-card__body { padding: var(--space-4); display: flex; flex-direction: column; flex: 1; gap: var(--space-2); }
.product-card__tags { display: flex; flex-wrap: wrap; gap: var(--space-1); }
.product-card__title {
  font-family: var(--font-body);
  text-transform: none;
  letter-spacing: 0;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0;
}
.product-card__title a { color: var(--text); text-decoration: none; }
.product-card__title a:hover { color: var(--info-text); }
.product-card__title a::after { content: ""; position: absolute; inset: 0; } /* whole card clickable */
.product-card { position: relative; }
.product-card__fit { color: var(--text-muted); font-size: .875rem; }
.product-card__footer {
  margin-top: auto;
  padding-top: var(--space-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.price { font-family: var(--font-heading); font-size: 1.5rem; font-weight: 700; letter-spacing: .01em; }
.product-card .btn { position: relative; z-index: 1; }

.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  background: var(--surface-3);
  color: var(--text-muted);
}
.tag--titanium { background: rgba(90, 169, 255, .15); color: var(--info-text); }
.tag--valved   { background: rgba(255, 90, 31, .15); color: var(--accent-text); }

.shop-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: var(--space-6);
  align-items: start;
}
.shop-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}
.shop-toolbar .search-form { flex: 1 1 260px; max-width: none; }
.shop-toolbar__sort { display: flex; align-items: center; gap: var(--space-2); }
.shop-toolbar__sort select { width: auto; min-width: 180px; }
.shop-count { color: var(--text-muted); font-size: .9rem; margin: 0 0 var(--space-4); }
.filters-toggle { display: none; }

.filters {
  position: sticky;
  top: calc(var(--header-h) + var(--space-4));
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-4);
}
.filters__head { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-3); }
.filters__head h2 { font-size: 1.3rem; margin: 0; }
.filters__close { display: none; }
.filter-group { border: 0; padding: 0; margin: 0 0 var(--space-4); min-width: 0; }
.filter-group:last-child { margin-bottom: 0; }
.filter-group legend {
  font-family: var(--font-heading);
  text-transform: uppercase;
  letter-spacing: .1em;
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-muted);
  padding: 0;
  margin-bottom: var(--space-2);
}
.filter-option {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 0;
  font-size: .95rem;
  cursor: pointer;
}
.filter-option input { width: 16px; height: 16px; margin: 0; accent-color: var(--accent); flex-shrink: 0; }
.filter-option .count { margin-left: auto; color: var(--text-faint); font-size: .8rem; }
.filters__reset { margin-top: var(--space-3); }

.empty-state {
  padding: var(--space-8) var(--space-4);
  text-align: center;
  background: var(--surface);
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius);
}
.empty-state h3 { margin-bottom: var(--space-2); }
.empty-state p { color: var(--text-muted); max-width: 48ch; margin: 0 auto var(--space-4); }

.skeleton {
  min-height: 320px;
  border-radius: var(--radius);
  background: linear-gradient(90deg, var(--surface) 25%, var(--surface-2) 50%, var(--surface) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite linear;
}
@keyframes shimmer { from { background-position: 200% 0; } to { background-position: -200% 0; } }
@media (prefers-reduced-motion: reduce) { .skeleton { animation: none; } html { scroll-behavior: auto; } }

@media (max-width: 899px) {
  .shop-layout { grid-template-columns: 1fr; }
  .filters-toggle { display: inline-flex; }
  .filters {
    position: fixed;
    inset: 0;
    top: auto;
    z-index: 60;
    max-height: 85vh;
    overflow-y: auto;
    border-radius: var(--radius-l) var(--radius-l) 0 0;
    box-shadow: var(--shadow);
    transform: translateY(105%);
    visibility: hidden;                       /* keep closed-sheet controls out of the tab order */
    transition: transform .25s ease, visibility 0s linear .25s;
    padding-bottom: calc(var(--space-6) + env(safe-area-inset-bottom));
  }
  .filters.is-open { transform: none; visibility: visible; transition-delay: 0s; }
  .filters__close { display: inline-flex; }
  .filters-backdrop {
    position: fixed; inset: 0; z-index: 55;
    background: rgba(0, 0, 0, .6);
    display: none;
  }
  .filters-backdrop.is-open { display: block; }
  body.filters-open { overflow: hidden; }
}

/* ---------- 8. Product ----------------------------------------------------- */
.breadcrumb {
  display: flex; flex-wrap: wrap; gap: var(--space-2);
  list-style: none; padding: 0; margin: 0 0 var(--space-5);
  font-size: .875rem; color: var(--text-muted);
}
.breadcrumb li + li::before { content: "/"; margin-right: var(--space-2); color: var(--text-faint); }
.breadcrumb a { color: var(--text-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--text); }

.product-layout {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: var(--space-7);
  align-items: start;
}
.product-media {
  position: sticky;
  top: calc(var(--header-h) + var(--space-4));
  background: radial-gradient(80% 90% at 50% 100%, var(--surface-3), var(--surface) 80%);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: var(--space-6);
  aspect-ratio: 4 / 3;
  display: flex;
  align-items: center;
}
.product-media img { width: 100%; height: 100%; object-fit: contain; }
.product-info h1 { font-size: clamp(1.9rem, 3.5vw, 2.6rem); }
.product-fitment {
  display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-3);
  color: var(--text-muted); margin-bottom: var(--space-4); font-size: .95rem;
}
.product-fitment strong { color: var(--text); font-weight: 600; }
.product-price { font-size: 2.2rem; margin-bottom: var(--space-4); }
.product-description { color: var(--text-muted); margin-bottom: var(--space-5); }

.variants { margin-bottom: var(--space-5); }
.variants__label { display: block; margin-bottom: var(--space-2); color: var(--text-muted); font-size: .9rem; }
.variants__list { display: flex; flex-wrap: wrap; gap: var(--space-2); list-style: none; padding: 0; margin: 0; }
.variant {
  display: inline-flex; flex-direction: column; gap: 2px;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-s);
  color: var(--text);
  text-decoration: none;
  font-size: .9rem;
  min-width: 140px;
}
.variant:hover { border-color: var(--text); color: var(--text); }
.variant[aria-current="true"] { border-color: var(--accent); background: rgba(255, 90, 31, .08); }
.variant small { color: var(--text-muted); }

.buy-row { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-3); margin-bottom: var(--space-3); }
.buy-row .btn--primary { flex: 1 1 200px; }
.buy-feedback { min-height: 1.5em; font-size: .95rem; color: var(--success); margin-bottom: var(--space-4); }
.buy-feedback a { color: inherit; }

.product-notes { display: grid; gap: var(--space-3); margin-bottom: var(--space-5); }
.product-note {
  display: flex; gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  font-size: .9rem;
  color: var(--text-muted);
}
.product-note svg { width: 20px; height: 20px; flex-shrink: 0; color: var(--info); margin-top: 2px; }

.feature-list { list-style: none; padding: 0; margin: 0 0 var(--space-5); }
.feature-list li {
  position: relative;
  padding-left: 26px;
  margin-bottom: var(--space-2);
}
.feature-list li::before {
  content: "";
  position: absolute; left: 0; top: .45em;
  width: 14px; height: 8px;
  border-left: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  transform: rotate(-45deg);
}

@media (max-width: 899px) {
  .product-layout { grid-template-columns: 1fr; gap: var(--space-5); }
  .product-media { position: static; padding: var(--space-4); }
}

/* ---------- 9. Cart -------------------------------------------------------- */
.cart-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: var(--space-6);
  align-items: start;
}
.cart-lines { list-style: none; padding: 0; margin: 0; }
.cart-line {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr) auto;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--border);
}
.cart-line__media {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: var(--space-2);
  aspect-ratio: 4 / 3;
  display: flex; align-items: center;
}
.cart-line__title {
  font-family: var(--font-body);
  text-transform: none;
  letter-spacing: 0;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 var(--space-1);
}
.cart-line__title a { color: var(--text); text-decoration: none; }
.cart-line__title a:hover { color: var(--info-text); }
.cart-line__meta { color: var(--text-muted); font-size: .875rem; margin-bottom: var(--space-3); }
.cart-line__controls { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-3); }
.cart-line__remove {
  background: none; border: 0; padding: 0;
  color: var(--text-muted); text-decoration: underline; cursor: pointer; font: inherit; font-size: .875rem;
}
.cart-line__remove:hover { color: var(--danger-text); }
.cart-line__total { text-align: right; }
.cart-line__total .price { font-size: 1.25rem; }
.cart-line__unit { color: var(--text-muted); font-size: .8rem; }

.summary {
  position: sticky;
  top: calc(var(--header-h) + var(--space-4));
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-5);
}
.summary h2 { font-size: 1.5rem; }
.summary-row { display: flex; justify-content: space-between; gap: var(--space-3); padding: var(--space-2) 0; }
.summary-row--total { border-top: 1px solid var(--border); margin-top: var(--space-2); padding-top: var(--space-3); font-weight: 600; }
.summary-row--total .price { font-size: 1.6rem; }
.summary .field { margin: var(--space-3) 0 var(--space-4); }
.summary .notice { margin-top: var(--space-3); }
.summary-actions { display: grid; gap: var(--space-3); margin-top: var(--space-4); }
.summary-help { font-size: .85rem; color: var(--text-muted); margin-top: var(--space-3); }

@media (max-width: 899px) {
  .cart-layout { grid-template-columns: 1fr; }
  .summary { position: static; }
}
@media (max-width: 479px) {
  .cart-line { grid-template-columns: 88px minmax(0, 1fr); }
  .cart-line__total { grid-column: 2; text-align: left; }
}

/* ---------- 10. Success / content pages ----------------------------------- */
.page-head { padding: var(--space-7) 0 var(--space-5); border-bottom: 1px solid var(--border); margin-bottom: var(--space-6); }
.page-head h1 { margin-bottom: var(--space-2); }
.page-head p { color: var(--text-muted); max-width: 60ch; margin: 0; }

.prose { max-width: 72ch; }
.prose h2 { font-size: 1.7rem; margin-top: var(--space-6); }
.prose h3 { font-size: 1.3rem; margin-top: var(--space-5); }
.prose p, .prose ul, .prose ol { color: var(--text-muted); }
.prose strong { color: var(--text); }
.prose .todo {
  display: inline-block;
  background: rgba(255, 90, 31, .12);
  color: var(--accent-text);
  border: 1px dashed rgba(255, 90, 31, .5);
  border-radius: var(--radius-s);
  padding: 0 6px;
  font-size: .85em;
}
.prose table { width: 100%; border-collapse: collapse; margin: var(--space-4) 0; font-size: .95rem; }
.prose th, .prose td { text-align: left; padding: var(--space-2) var(--space-3); border-bottom: 1px solid var(--border); }
.prose th { color: var(--text); font-weight: 600; }

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-5);
}
.contact-card {
  padding: var(--space-5);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.contact-card h3 { font-size: 1.3rem; }
.contact-card p { color: var(--text-muted); font-size: .95rem; }
.contact-card a { word-break: break-word; }

.order-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-5);
  max-width: 640px;
}
.order-card h2 { font-size: 1.5rem; }
.order-items { list-style: none; padding: 0; margin: 0 0 var(--space-3); }
.order-items li { display: flex; justify-content: space-between; gap: var(--space-3); padding: var(--space-2) 0; border-bottom: 1px solid var(--border); }
.order-meta { color: var(--text-muted); font-size: .9rem; }

.status-block { max-width: 640px; }
.status-block .btn { margin-top: var(--space-4); }

.not-found { text-align: center; padding: var(--space-9) 0; }
.not-found h1 { font-size: clamp(3rem, 12vw, 7rem); color: var(--accent-text); margin-bottom: 0; }
.not-found p { color: var(--text-muted); max-width: 48ch; margin: var(--space-3) auto var(--space-5); }
.not-found .actions { display: flex; flex-wrap: wrap; justify-content: center; gap: var(--space-3); }

/* ---------- 11. Utilities -------------------------------------------------- */
.row { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: center; }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
[hidden] { display: none !important; }

/* ---------- 12. Light mode ------------------------------------------------- */
@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --bg:            #f5f5f7;
    --bg-elevated:   #ffffff;
    --surface:       #ffffff;
    --surface-2:     #eef0f3;
    --surface-3:     #e3e6ea;
    --border:        #dcdfe4;
    --border-strong: #b9bec8;
    --text:          #15171c;
    --text-muted:    #545a67;
    --text-faint:    #7a808c;
    --accent-text:   #c43f0b;
    --info:          #1f6fd1;
    --info-text:     #1a5fb4;
    --success:       #177a4d;
    --danger:        #c62828;
    --danger-text:   #b71c1c;
    --focus:         #1f6fd1;
    --shadow:        0 10px 30px rgba(20, 24, 35, .18);
  }
  .hero {
    background:
      radial-gradient(60% 80% at 85% 20%, rgba(255, 90, 31, .16), transparent 60%),
      radial-gradient(40% 60% at 10% 90%, rgba(31, 111, 209, .10), transparent 60%),
      var(--bg);
  }
  .hero-art img { filter: drop-shadow(0 24px 30px rgba(20, 24, 35, .3)); }
  .tag--titanium { background: rgba(31, 111, 209, .12); }
  .tag--valved   { background: rgba(255, 90, 31, .14); }
  .variant[aria-current="true"] { background: rgba(255, 90, 31, .08); }
  .prose .todo { background: rgba(255, 90, 31, .1); }
  .notice--danger { color: var(--danger-text); }
  .buy-feedback { color: var(--success); }
}