/* ============================================================
   SWZL SYSTEM — Design Tokens
   Concept: nighttime highway work-zone safety. Dark, technical,
   amber LED-glow accent (matches the product's own light).
   ============================================================ */

:root {
  /* Fluid type scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 4.5rem);
  --text-hero: clamp(2.75rem, 0.8rem + 6vw, 6.5rem);

  /* 4px spacing system */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.3rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.85rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1240px;
  --content-full: 100%;

  /* Fonts */
  --font-display: 'Cabinet Grotesk', 'Segoe UI', sans-serif;
  --font-body: 'Satoshi', 'Helvetica Neue', sans-serif;
}

/* Dark is the default brand mode — nighttime work zone */
:root,
[data-theme='dark'] {
  --color-bg: #0a0d12;
  --color-surface: #12161d;
  --color-surface-2: #171c24;
  --color-surface-offset: #1d232d;
  --color-divider: #1e242e;
  --color-border: #262c37;

  --color-text: #edeff2;
  --color-text-muted: #9aa2b1;
  --color-text-faint: #666e7d;
  --color-text-inverse: #14161a;

  --color-primary: #fbbf24;
  --color-primary-hover: #fdd463;
  --color-primary-active: #fee29a;
  --color-primary-highlight: #332a11;
  --color-on-primary: #14161a;

  --color-success: #6daa45;
  --color-error: #d1687a;

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.4);
  --shadow-md: 0 8px 20px oklch(0 0 0 / 0.45);
  --shadow-lg: 0 20px 48px oklch(0 0 0 / 0.55);
}

[data-theme='light'] {
  --color-bg: #f6f5f1;
  --color-surface: #ffffff;
  --color-surface-2: #f1efe9;
  --color-surface-offset: #eae7de;
  --color-divider: #e4e1d8;
  --color-border: #ddd8cd;

  --color-text: #181a1d;
  --color-text-muted: #565e6b;
  --color-text-faint: #8a90a0;
  --color-text-inverse: #f7f7f5;

  --color-primary: #8a4a06;
  --color-primary-hover: #6c3a04;
  --color-primary-active: #522c03;
  --color-primary-highlight: #f4e3c6;
  --color-on-primary: #fefaf3;

  --color-success: #437a22;
  --color-error: #a13544;

  --shadow-sm: 0 1px 2px oklch(0.2 0.02 80 / 0.08);
  --shadow-md: 0 8px 20px oklch(0.2 0.02 80 / 0.1);
  --shadow-lg: 0 20px 48px oklch(0.2 0.02 80 / 0.14);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg: #f6f5f1;
    --color-surface: #ffffff;
    --color-surface-2: #f1efe9;
    --color-surface-offset: #eae7de;
    --color-divider: #e4e1d8;
    --color-border: #ddd8cd;
    --color-text: #181a1d;
    --color-text-muted: #565e6b;
    --color-text-faint: #8a90a0;
    --color-text-inverse: #f7f7f5;
    --color-primary: #8a4a06;
    --color-primary-hover: #6c3a04;
    --color-primary-active: #522c03;
    --color-primary-highlight: #f4e3c6;
    --color-on-primary: #fefaf3;
    --shadow-sm: 0 1px 2px oklch(0.2 0.02 80 / 0.08);
    --shadow-md: 0 8px 20px oklch(0.2 0.02 80 / 0.1);
    --shadow-lg: 0 20px 48px oklch(0.2 0.02 80 / 0.14);
  }
}

/* ============================================================
   Base layout
   ============================================================ */

body {
  overflow-x: hidden;
}

.wrap {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

section {
  position: relative;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.eyebrow::before {
  content: '';
  width: 18px;
  height: 1px;
  background: var(--color-primary);
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.01em;
}

p {
  color: var(--color-text-muted);
}

a {
  color: inherit;
  text-decoration: none;
}

.tabular {
  font-variant-numeric: tabular-nums lining-nums;
}

/* ============================================================
   Header
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: oklch(from var(--color-bg) l c h / 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-divider);
  transition:
    transform 0.3s cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.site-header.is-hidden {
  transform: translateY(-100%);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  padding-block: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  letter-spacing: 0.02em;
  color: var(--color-text);
}
.brand svg {
  width: 30px;
  height: 30px;
  color: var(--color-primary);
  flex-shrink: 0;
}
.brand .tag {
  display: block;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
  color: var(--color-text-faint);
  text-transform: none;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}
.main-nav ul {
  display: flex;
  gap: var(--space-6);
}
.main-nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  padding-block: var(--space-1);
  border-bottom: 1px solid transparent;
}
.main-nav a:hover {
  color: var(--color-text);
  border-bottom-color: var(--color-border);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
}
.theme-toggle:hover {
  color: var(--color-text);
  border-color: var(--color-text-faint);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--text-sm);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  white-space: nowrap;
  min-height: 44px;
}
.btn-primary {
  background: var(--color-primary);
  color: var(--color-on-primary);
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  color: var(--color-on-primary);
}
[data-theme='dark'] .btn-primary:hover,
:root:not([data-theme]) .btn-primary:hover {
  color: var(--color-on-primary);
}
.btn-ghost {
  border: 1px solid var(--color-border);
  color: var(--color-text);
}
.btn-ghost:hover {
  border-color: var(--color-text-faint);
  background: var(--color-surface-2);
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
}

/* ============================================================
   Hero
   ============================================================ */

.hero {
  padding-block: clamp(var(--space-16), 8vw, var(--space-24)) clamp(var(--space-12), 6vw, var(--space-20));
  border-bottom: 1px solid var(--color-divider);
}

.hero .wrap {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: var(--space-16);
  align-items: center;
}

.hero-copy h1 {
  font-size: var(--text-hero);
  margin-bottom: var(--space-6);
}
.hero-copy h1 .accent {
  color: var(--color-primary);
}

.hero-copy .lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 46ch;
  margin-bottom: var(--space-8);
}

.hero-eyebrow {
  margin-bottom: var(--space-5);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-bottom: var(--space-10);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6) var(--space-8);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-divider);
}
.hero-meta-item .num {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  display: block;
}
.hero-meta-item .label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.hero-visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-divider);
  aspect-ratio: 4 / 5;
}
.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-visual .caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-5) var(--space-6);
  background: linear-gradient(to top, oklch(0 0 0 / 0.75), transparent);
  color: #f4f4f2;
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
}

/* ============================================================
   Message band (full-bleed image)
   ============================================================ */

.message-band {
  position: relative;
  width: 100%;
  height: min(62vh, 620px);
  min-height: 320px;
  overflow: hidden;
  margin: 0;
  border-block: 1px solid var(--color-divider);
}
.message-band img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  display: block;
}
.message-band figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-8) var(--space-6);
  background: linear-gradient(to top, oklch(0 0 0 / 0.8), transparent 70%);
  color: #f4f4f2;
}
.message-band figcaption .eyebrow {
  color: #fbbf24;
}
.message-band figcaption p {
  margin-top: var(--space-2);
  max-width: 40ch;
  color: #f4f4f2;
  font-size: var(--text-lg);
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.01em;
}
@media (max-width: 640px) {
  .message-band {
    height: 60vh;
  }
  .message-band figcaption p {
    font-size: var(--text-base);
    max-width: 28ch;
  }
}

/* ============================================================
   Stat strip
   ============================================================ */

.stat-strip {
  padding-block: var(--space-10);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-divider);
}
.stat-strip .wrap {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: var(--space-12);
  align-items: center;
}
.stat-big {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  color: var(--color-primary);
  line-height: 1;
}
.stat-strip p {
  max-width: 60ch;
}
.stat-strip .source {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-3);
}
.stat-strip .source a {
  color: var(--color-text-faint);
  border-bottom: 1px solid var(--color-border);
}
.stat-strip .source a:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ============================================================
   Section shell
   ============================================================ */

.section {
  padding-block: clamp(var(--space-16), 9vw, var(--space-32));
}
.section-alt {
  background: var(--color-surface);
  border-block: 1px solid var(--color-divider);
}
.section-head {
  max-width: 62ch;
  margin-bottom: clamp(var(--space-10), 5vw, var(--space-16));
}
.section-head h2 {
  font-size: var(--text-2xl);
  margin-top: var(--space-4);
}
.section-head p {
  margin-top: var(--space-4);
  font-size: var(--text-lg);
}

/* ============================================================
   Product section — asymmetric feature narrative
   ============================================================ */

.product-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: var(--space-16);
  align-items: start;
}
.product-visual {
  position: sticky;
  top: calc(var(--space-24));
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--color-divider);
  box-shadow: var(--shadow-md);
}
.product-visual img {
  width: 100%;
  height: auto;
}

.feature-row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-6);
  padding-block: var(--space-8);
  border-top: 1px solid var(--color-divider);
}
.feature-row:first-child {
  border-top: none;
  padding-top: 0;
}
.feature-index {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text-faint);
  min-width: 2.5ch;
}
.feature-row h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}
.feature-row p {
  font-size: var(--text-base);
}
.feature-specs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-5);
  margin-top: var(--space-4);
}
.feature-specs span {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  padding-block: var(--space-1);
  border-bottom: 1px dashed var(--color-border);
}

/* ============================================================
   How it works — mesh diagram
   ============================================================ */

.how-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
}
.mesh-diagram {
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-xl);
  background: var(--color-surface);
  padding: var(--space-8);
}
.mesh-diagram svg {
  width: 100%;
  height: auto;
}

.how-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}
.how-item h4 {
  font-size: var(--text-base);
  color: var(--color-text);
  margin-bottom: var(--space-1);
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
}
.how-item h4 .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  flex-shrink: 0;
}
.how-item p {
  font-size: var(--text-sm);
  padding-left: calc(6px + var(--space-2));
}

/* ============================================================
   EDC-8 alignment
   ============================================================ */

.alignment-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--color-divider);
}
.alignment-row {
  display: grid;
  grid-template-columns: 0.9fr 1.4fr 0.9fr;
  gap: var(--space-8);
  padding-block: var(--space-6);
  border-bottom: 1px solid var(--color-divider);
  align-items: baseline;
}
.alignment-row .edc-label {
  font-family: var(--font-display);
  font-size: var(--text-base);
  color: var(--color-text);
}
.alignment-row .swzl-answer p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.alignment-row .edc-cite {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-align: right;
}
.alignment-row .edc-cite a {
  color: var(--color-text-faint);
  border-bottom: 1px solid var(--color-border);
}
.alignment-row .edc-cite a:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ============================================================
   Spec grid
   ============================================================ */

.spec-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--color-divider);
  border-left: 1px solid var(--color-divider);
}
.spec-cell {
  padding: var(--space-8) var(--space-6);
  border-right: 1px solid var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}
.spec-cell .val {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text);
  display: block;
}
.spec-cell .label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-2);
}

/* ============================================================
   Roadmap
   ============================================================ */

.roadmap {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}
.roadmap-step {
  padding: var(--space-8) var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
}
.roadmap-step .stage {
  font-size: var(--text-xs);
  color: var(--color-primary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
}
.roadmap-step h3 {
  font-size: var(--text-lg);
  margin-block: var(--space-3) var(--space-2);
}
.roadmap-step p {
  font-size: var(--text-sm);
}
.roadmap-note {
  margin-top: var(--space-10);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 70ch;
}

/* ============================================================
   Contact / CTA
   ============================================================ */

.contact-panel {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-16);
  padding: clamp(var(--space-10), 6vw, var(--space-16));
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-xl);
}
.contact-panel h2 {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-4);
}
.contact-panel .lede {
  font-size: var(--text-base);
  max-width: 52ch;
}
.contact-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  justify-content: center;
}
.contact-link {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--color-divider);
}
.contact-link:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.contact-link .label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.contact-link .value {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
}
.contact-link a.value:hover {
  color: var(--color-primary);
}

/* ============================================================
   Footer
   ============================================================ */

.site-footer {
  padding-block: var(--space-12);
  border-top: 1px solid var(--color-divider);
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-8);
  flex-wrap: wrap;
  padding-bottom: var(--space-8);
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-text);
}
.footer-brand svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary);
}
.footer-nav {
  display: flex;
  gap: var(--space-6);
  flex-wrap: wrap;
}
.footer-nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.footer-nav a:hover {
  color: var(--color-text);
}
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-divider);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.footer-sources {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}
.footer-sources a {
  color: var(--color-text-faint);
  border-bottom: 1px solid var(--color-border);
}
.footer-sources a:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ============================================================
   Reveal-on-scroll
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ============================================================
   Skip link
   ============================================================ */

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  z-index: 200;
  background: var(--color-primary);
  color: var(--color-on-primary);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
}
.skip-link:focus {
  top: var(--space-4);
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 980px) {
  .main-nav ul {
    display: none;
  }
  .main-nav.is-open ul {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: var(--space-1);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-divider);
    padding: var(--space-6);
    box-shadow: var(--shadow-md);
  }
  .main-nav.is-open ul a {
    display: block;
    padding-block: var(--space-3);
    font-size: var(--text-base);
  }
  .hero .wrap {
    grid-template-columns: 1fr;
  }
  .hero-visual {
    order: -1;
    aspect-ratio: 16 / 10;
  }
  .stat-strip .wrap {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  .product-layout,
  .how-layout {
    grid-template-columns: 1fr;
  }
  .product-visual {
    position: static;
  }
  .alignment-row {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  .alignment-row .edc-cite {
    text-align: left;
  }
  .spec-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .roadmap {
    grid-template-columns: 1fr;
  }
  .contact-panel {
    grid-template-columns: 1fr;
  }
  .nav-toggle {
    display: flex;
  }
}

@media (max-width: 640px) {
  #header-cta,
  .header-actions .btn-primary {
    display: none;
  }
}

@media (max-width: 560px) {
  .spec-grid {
    grid-template-columns: 1fr 1fr;
  }
  .hero-meta {
    gap: var(--space-5);
  }
}