/* ==========================================================================
   1. Custom Properties
   ========================================================================== */

:root {
  /* Static palette */
  --color-slate: #0F172A;
  --color-slate-light: #1E293B;
  --color-slate-lighter: #334155;
  --color-indigo: #6366F1;
  --color-indigo-light: #818CF8;
  --color-cyan: #22D3EE;
  --color-green: #10B981;
  --color-amber: #F59E0B;
  --color-white: #FFFFFF;
  --color-gray-100: #F1F5F9;
  --color-gray-200: #E2E8F0;
  --color-gray-300: #CBD5E1;
  --color-gray-400: #94A3B8;
  --color-gray-500: #64748B;
  --color-gray-600: #475569;
  --color-gray-800: #1E293B;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'Cascadia Code', monospace;
  --font-display: 'Space Frigate', var(--font-mono);

  /* Transitions */
  --transition-theme: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
  --transition-fast: 0.15s ease;
  --transition-base: 0.2s ease;

  /* Nav */
  --nav-height: 4rem;

  /* Border radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
}

/* Dark theme (default) */
[data-theme="dark"] {
  --bg-primary: var(--color-slate);
  --bg-secondary: var(--color-slate-light);
  --bg-card: var(--color-slate-light);
  --bg-nav: rgba(15, 23, 42, 0.85);
  --text-primary: var(--color-gray-100);
  --text-secondary: var(--color-gray-400);
  --text-muted: var(--color-gray-500);
  --border-color: var(--color-slate-lighter);
  --border-subtle: rgba(255, 255, 255, 0.06);
}

/* Light theme */
[data-theme="light"] {
  --bg-primary: var(--color-white);
  --bg-secondary: var(--color-gray-100);
  --bg-card: var(--color-white);
  --bg-nav: rgba(255, 255, 255, 0.85);
  --text-primary: var(--color-slate);
  --text-secondary: var(--color-gray-600);
  --text-muted: var(--color-gray-500);
  --border-color: var(--color-gray-200);
  --border-subtle: rgba(0, 0, 0, 0.06);
}

/* ==========================================================================
   2. Reset & Base
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: var(--transition-theme);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

button {
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
  font: inherit;
}

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: 200;
  padding: 0.5rem 1rem;
  background: var(--color-indigo);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

/* ---------- Focus styles ---------- */
:focus-visible {
  outline: 2px solid var(--color-cyan);
  outline-offset: 2px;
}

/* Remove default outline only when :focus-visible is supported */
:focus:not(:focus-visible) {
  outline: none;
}

/* ---------- Screen reader only ---------- */
.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;
}

/* ==========================================================================
   3. Layout
   ========================================================================== */

.container {
  width: 100%;
  max-width: 80rem;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ==========================================================================
   4. Navigation
   ========================================================================== */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: var(--transition-theme);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav__mark {
  flex-shrink: 0;
}

.nav__wordmark {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--text-primary);
}

.nav__dot {
  color: var(--color-cyan);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  list-style: none;
}

.nav__links li {
  display: contents;
}

.nav__link {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--text-primary);
}

.nav__toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.nav__toggle svg {
  width: 16px;
  height: 16px;
}

.nav__toggle:hover {
  background-color: var(--border-subtle);
}

/* Show sun icon in dark mode, moon in light */
[data-theme="dark"] .icon--moon { display: none; }
[data-theme="dark"] .icon--sun { display: block; }
[data-theme="light"] .icon--sun { display: none; }
[data-theme="light"] .icon--moon { display: block; }

/* ==========================================================================
   5. Hero
   ========================================================================== */

.hero {
  min-height: 80vh;
  display: flex;
  align-items: center;
  padding-top: calc(var(--nav-height) + var(--space-3xl));
  padding-bottom: var(--space-3xl);
}

.hero__inner {
  max-width: 52rem;
}

.hero__headline {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: normal;
  line-height: 1.15;
  letter-spacing: 0.02em;
  background: linear-gradient(135deg, var(--color-indigo) 0%, var(--color-cyan) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-md);
}

.hero__subheadline {
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.hero__description {
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  color: var(--text-secondary);
  max-width: 40rem;
  margin-bottom: var(--space-xl);
  line-height: 1.7;
}

.hero__ctas {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

/* ==========================================================================
   6. Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.75rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  white-space: nowrap;
}

.btn--primary {
  background-color: var(--color-indigo);
  color: var(--color-white);
}

.btn--primary:hover {
  background-color: var(--color-indigo-light);
  transform: translateY(-1px);
}

.btn--outline {
  border: 1.5px solid var(--border-color);
  color: var(--text-primary);
}

.btn--outline:hover {
  border-color: var(--color-indigo);
  color: var(--color-indigo);
  transform: translateY(-1px);
}

/* ==========================================================================
   7. Services
   ========================================================================== */

.services {
  padding: var(--space-3xl) 0;
}

.services__headline {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: normal;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-2xl);
}

.services__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.services__card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-top: 3px solid var(--card-accent, var(--color-indigo));
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: var(--transition-theme), transform var(--transition-base), box-shadow var(--transition-base);
}

.services__card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
}

/* Accent colors */
.services__card--indigo { --card-accent: var(--color-indigo); }
.services__card--cyan   { --card-accent: var(--color-cyan); }
.services__card--green  { --card-accent: var(--color-green); }
.services__card--amber  { --card-accent: var(--color-amber); }

.services__title {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.services__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--card-accent, var(--color-indigo));
  margin-bottom: var(--space-xs);
}

.services__problem,
.services__solution {
  margin-bottom: var(--space-sm);
}

.services__problem p,
.services__solution p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   8. Contact
   ========================================================================== */

.contact {
  padding: var(--space-3xl) 0;
}

.contact__inner {
  text-align: center;
  max-width: 36rem;
  margin: 0 auto;
}

.contact__headline {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: normal;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-sm);
}

.contact__description {
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: var(--space-xl);
}

.contact__email {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--color-indigo);
  transition: color var(--transition-fast);
}

.contact__email:hover {
  color: var(--color-indigo-light);
}

.contact__social {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-top: var(--space-xl);
  list-style: none;
}

.contact__social li {
  display: contents;
}

.contact__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.contact__social-link:hover {
  color: var(--color-indigo);
  background-color: var(--border-subtle);
}

/* ==========================================================================
   9. Footer
   ========================================================================== */

.footer {
  border-top: 1px solid var(--border-color);
  padding: var(--space-lg) 0;
  transition: var(--transition-theme);
}

.footer__inner {
  text-align: center;
}

.footer__copy {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer__brand {
  font-family: var(--font-display);
}

.footer__dot {
  color: var(--color-cyan);
}

.footer__links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-top: var(--space-xs);
}

.footer__link {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-cyan);
}

/* ==========================================================================
   10. Content pages
   ========================================================================== */

.page {
  padding-top: calc(var(--nav-height) + var(--space-3xl));
  padding-bottom: var(--space-3xl);
}

.page__inner {
  max-width: 42rem;
}

.page__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: normal;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-xs);
}

.page__subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-2xl);
}

.page__content h2 {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

.page__content p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-sm);
}

.page__content a {
  color: var(--color-indigo);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.page__content a:hover {
  color: var(--color-cyan);
}

.page__updated {
  margin-top: var(--space-2xl);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ==========================================================================
   11. Responsive
   ========================================================================== */

/* Mobile nav fix */
@media (max-width: 39.999rem) {
  .nav__wordmark {
    display: none;
  }

  .nav__links {
    gap: var(--space-sm);
  }
}

/* Tablet */
@media (min-width: 40rem) {
  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Desktop */
@media (min-width: 64rem) {
  .container {
    padding: 0 var(--space-lg);
  }

  .services__grid {
    gap: var(--space-lg);
  }
}

/* Wide */
@media (min-width: 80rem) {
  .services__grid {
    grid-template-columns: repeat(4, 1fr);
  }
}