:root {
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #eff6ff;
  --color-accent: #f59e0b;
  --color-surface: #ffffff;
  --color-surface-alt: #f8fafc;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-tertiary: #94a3b8;
  --color-text-on-primary: #ffffff;
  --color-ad-bg: #f1f5f9;
  --color-ad-label: #94a3b8;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-pill: 9999px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 1px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 6px 24px rgba(15, 23, 42, 0.08), 0 2px 4px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 24px 64px rgba(15, 23, 42, 0.18), 0 6px 16px rgba(15, 23, 42, 0.08);
  --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --max-content: 1120px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
}

[data-theme='dark'] {
  --color-primary: #3b82f6;
  --color-primary-hover: #60a5fa;
  --color-primary-light: rgba(59, 130, 246, 0.12);
  --color-accent: #fbbf24;
  --color-surface: #0f172a;
  --color-surface-alt: #1e293b;
  --color-border: #334155;
  --color-border-strong: #475569;
  --color-text-primary: #f1f5f9;
  --color-text-secondary: #cbd5e1;
  --color-text-tertiary: #94a3b8;
  --color-ad-bg: #1e293b;
  --color-ad-label: #64748b;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 24px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.6);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']):not([data-theme='dark']) {
    --color-primary: #3b82f6;
    --color-primary-hover: #60a5fa;
    --color-primary-light: rgba(59, 130, 246, 0.12);
    --color-surface: #0f172a;
    --color-surface-alt: #1e293b;
    --color-border: #334155;
    --color-border-strong: #475569;
    --color-text-primary: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-tertiary: #94a3b8;
    --color-ad-bg: #1e293b;
    --color-ad-label: #64748b;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: 'DM Sans', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica,
    Arial, sans-serif;
  background: var(--color-surface);
  color: var(--color-text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--ease-standard) 200ms, color var(--ease-standard) 200ms;
}

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

h1,
h2,
h3 {
  font-family: 'DM Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
  letter-spacing: -0.02em;
  margin: 0;
}

/* ===== Header ============================================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-5) var(--space-8);
  background: color-mix(in srgb, var(--color-surface) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text-primary);
  font-weight: 700;
}
.brand:hover {
  color: var(--color-text-primary);
}
.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #ffffff;
  font-weight: 700;
  font-size: 18px;
  box-shadow: var(--shadow-sm);
}
.brand__name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}
.nav a {
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: 15px;
}
.nav a:hover {
  color: var(--color-text-primary);
}

.theme-toggle {
  border: 1px solid var(--color-border);
  background: var(--color-surface-alt);
  color: var(--color-text-primary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  display: inline-grid;
  place-items: center;
  transition: transform var(--ease-standard) 200ms,
    background var(--ease-standard) 200ms;
}
.theme-toggle:hover {
  transform: scale(1.05);
}

/* ===== Hero ============================================================== */
.hero {
  padding: var(--space-20) var(--space-6) var(--space-16);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 480px;
  background: radial-gradient(
      80% 60% at 30% 0%,
      color-mix(in srgb, var(--color-primary) 22%, transparent) 0%,
      transparent 60%
    ),
    radial-gradient(
      60% 50% at 80% 10%,
      color-mix(in srgb, var(--color-accent) 18%, transparent) 0%,
      transparent 65%
    );
  z-index: -1;
}

.hero__inner {
  max-width: var(--max-content);
  margin: 0 auto;
  text-align: center;
}

.pill {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: var(--space-6);
  border: 1px solid color-mix(in srgb, var(--color-primary) 25%, transparent);
}

.hero h1 {
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1.05;
  font-weight: 800;
  margin-bottom: var(--space-5);
}
.hero__accent {
  background: linear-gradient(120deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__lede {
  max-width: 640px;
  margin: 0 auto var(--space-8);
  color: var(--color-text-secondary);
  font-size: clamp(16px, 1.6vw, 19px);
}

.hero__cta {
  display: inline-flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 15px;
  border: 1px solid transparent;
  transition: transform var(--ease-standard) 180ms,
    background var(--ease-standard) 180ms, color var(--ease-standard) 180ms;
}
.btn:hover {
  transform: translateY(-1px);
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-text-on-primary);
  box-shadow: var(--shadow-md);
}
.btn--primary:hover {
  background: var(--color-primary-hover);
  color: var(--color-text-on-primary);
}
.btn--ghost {
  background: transparent;
  color: var(--color-text-primary);
  border-color: var(--color-border-strong);
}
.btn--ghost:hover {
  background: var(--color-surface-alt);
}

/* ===== Sections ========================================================== */
.section {
  max-width: var(--max-content);
  margin: 0 auto;
  padding: var(--space-16) var(--space-6);
}

.section__header {
  text-align: center;
  margin-bottom: var(--space-10);
}
.section__header h2 {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 700;
  margin-bottom: var(--space-2);
}
.section__header p {
  color: var(--color-text-secondary);
  margin: 0;
}

/* ===== Cards ============================================================= */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.card {
  position: relative;
  display: block;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  color: var(--color-text-primary);
  transition: transform var(--ease-standard) 200ms,
    box-shadow var(--ease-standard) 200ms,
    border-color var(--ease-standard) 200ms;
}
.card:hover {
  color: var(--color-text-primary);
}
.card--featured:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: color-mix(in srgb, var(--color-primary) 35%, var(--color-border));
}

/* QRStudio — iridescent treatment so the card stands out next to ToolBox. */
.card--qrstudio {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(120% 80% at 100% 0%, rgba(124, 58, 237, 0.10) 0%, transparent 60%),
    radial-gradient(80% 60% at 0% 100%, rgba(6, 182, 212, 0.10) 0%, transparent 60%),
    var(--color-surface);
}
.card--qrstudio::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 40%, rgba(255, 255, 255, 0.08) 50%, transparent 60%);
  background-size: 200% 100%;
  pointer-events: none;
  transition: background-position 800ms ease;
  background-position: -100% 0;
}
.card--qrstudio:hover::after {
  background-position: 200% 0;
}
.card--qrstudio:hover {
  border-color: color-mix(in srgb, #7c3aed 50%, var(--color-border));
}
@keyframes iri-shift-pill {
  to { background-position: 200% 0; }
}
.card__badge--iri {
  background: linear-gradient(120deg, #06b6d4, #7c3aed, #ec4899, #f59e0b);
  background-size: 200% 200%;
  animation: iri-shift-pill 6s linear infinite;
  color: #ffffff;
  border-color: transparent;
}

.card__badge {
  position: absolute;
  top: var(--space-5);
  right: var(--space-5);
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-size: 12px;
  font-weight: 600;
  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
}
.card__badge--muted {
  background: var(--color-surface-alt);
  color: var(--color-text-tertiary);
  border-color: var(--color-border);
}

.card__icon {
  font-size: 36px;
  margin-bottom: var(--space-4);
}

.card__title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.card__desc {
  color: var(--color-text-secondary);
  margin: 0 0 var(--space-5);
  font-size: 15px;
}

.card__tags {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-5);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.card__tags li {
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 500;
}

.card__cta {
  display: inline-flex;
  align-items: center;
  font-weight: 600;
  font-size: 15px;
  color: var(--color-primary);
}
.card__cta--muted {
  color: var(--color-text-tertiary);
}

.card--soon {
  cursor: default;
  opacity: 0.85;
}

/* ===== Ad slot =========================================================== */
.section--ads {
  padding-top: 0;
}
.ad-slot {
  background: var(--color-ad-bg);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  text-align: center;
  min-height: 120px;
  position: relative;
}
.ad-slot__label {
  position: absolute;
  top: 6px;
  right: 12px;
  font-size: 10px;
  color: var(--color-ad-label);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ===== About ============================================================= */
.section--about .prose {
  max-width: 720px;
  margin: 0 auto;
  color: var(--color-text-secondary);
  font-size: 17px;
}
.section--about .prose p + p {
  margin-top: var(--space-4);
}

/* ===== Contact =========================================================== */
.contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-4);
  max-width: 720px;
  margin: 0 auto;
}
.contact__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: var(--space-5) var(--space-6);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text-primary);
  transition: transform var(--ease-standard) 200ms,
    border-color var(--ease-standard) 200ms;
}
.contact__item:hover {
  transform: translateY(-2px);
  border-color: var(--color-primary);
  color: var(--color-text-primary);
}
.contact__label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-tertiary);
}
.contact__value {
  font-weight: 600;
  font-size: 16px;
}

/* ===== Footer ============================================================ */
.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6);
  background: var(--color-surface-alt);
}
.footer__inner {
  max-width: var(--max-content);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: space-between;
  align-items: center;
  color: var(--color-text-secondary);
  font-size: 14px;
}
.footer__inner nav {
  display: flex;
  gap: var(--space-5);
}
.footer__inner nav a {
  color: var(--color-text-secondary);
}
.footer__inner nav a:hover {
  color: var(--color-text-primary);
}

/* ===== Responsive ======================================================== */
@media (max-width: 640px) {
  .header {
    padding: var(--space-4);
  }
  .nav {
    gap: var(--space-3);
  }
  .nav a {
    font-size: 14px;
  }
  .hero {
    padding-top: var(--space-12);
    padding-bottom: var(--space-10);
  }
  .section {
    padding: var(--space-12) var(--space-4);
  }
}