/* Design tokens */
:root {
  color-scheme: light dark;
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --bg: #f8fbff;
  --surface: #ffffff;
  --surface-muted: #edf4ff;
  --fg: #0f172a;
  --fg-muted: rgba(15, 23, 42, 0.72);
  --fg-subtle: rgba(15, 23, 42, 0.52);
  --accent: #0ea5e9;
  --accent-dark: #0284c7;
  --border: rgba(14, 165, 233, 0.18);
  --outline: rgba(14, 165, 233, 0.22);
  --success: #0f766e;
  --success-bg: rgba(13, 148, 136, 0.12);
  --radius-sm: 0.5rem;
  --radius-md: 0.9rem;
  --radius-pill: 999px;
  --shadow-card: 0 10px 30px -24px rgba(15, 23, 42, 0.35);
  --shadow-button: 0 12px 22px -12px rgba(67, 56, 202, 0.45);
  --shadow-button-hover: 0 18px 28px -20px rgba(67, 56, 202, 0.5);
  --transition-base: 0.2s ease;
  --container-max: 1280px;
  --container-gutter: clamp(1.5rem, 4vw, 3rem);
  --container-padding-block: clamp(2.5rem, 6vw, 4rem);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #050a11;
    --surface: #101826;
    --surface-muted: #111f33;
    --fg: #eff6ff;
    --fg-muted: rgba(239, 246, 255, 0.74);
    --fg-subtle: rgba(239, 246, 255, 0.58);
    --accent: #38bdf8;
    --accent-dark: #0ea5e9;
    --border: rgba(56, 189, 248, 0.26);
    --outline: rgba(56, 189, 248, 0.24);
    --success: #34d399;
    --success-bg: rgba(52, 211, 153, 0.12);
  }
}

/* Global reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
}

body {
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  display: block;
}

p {
  margin: 0 0 1.25rem;
  color: var(--fg-muted);
}

ul,
ol {
  margin: 0 0 1.25rem;
  padding-left: 1.25rem;
  color: var(--fg-muted);
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--fg);
  line-height: 1.1;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  letter-spacing: -0.04em;
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  letter-spacing: -0.03em;
}

h3 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  letter-spacing: -0.02em;
}

h4 {
  font-size: 1.125rem;
}

/* Accessibility helpers */
.sr-only,
.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;
}

.hidden {
  display: none !important;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip-link:focus-visible {
  left: 1rem;
  top: 1rem;
  width: auto;
  height: auto;
  padding: 0.6rem 1.1rem;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  z-index: 10;
}

/* Links */
a {
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 0.2em;
  transition: color var(--transition-base), text-decoration-color var(--transition-base);
}

a:hover,
a:focus-visible {
  color: var(--accent-dark);
  text-decoration: underline;
  text-decoration-color: rgba(99, 102, 241, 0.4);
}

/* Layout */
.container {
  width: min(var(--container-max), 92vw);
  margin: 0 auto;
  padding: var(--container-padding-block) var(--container-gutter);
}

.site-header,
.site-footer {
  background: var(--surface);
}

.site-header {
  border-bottom: 1px solid var(--border);
}

@media (prefers-color-scheme: dark) {
  .site-header {
    background: rgba(15, 23, 42, 0.9);
  }
}

.site-footer {
  box-shadow: inset 0 1px 0 rgba(15, 23, 42, 0.06);
}

.site-header .container,
.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem var(--container-gutter);
}

.site-footer .container {
  flex-direction: column;
  justify-content: center;
  text-align: center;
  gap: 0.75rem;
  padding: 0.75rem var(--container-gutter);
}

.site-header--minimal {
  background: transparent;
  border-bottom: none;
}

.site-header--minimal .container {
  padding: 0.6rem var(--container-gutter);
}

.footer-nav {
  margin: 0;
}

.footer-copy {
  margin: 0;
  color: var(--fg-subtle);
  font-size: 0.95rem;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.site-header__actions .pill {
  background: rgba(67, 56, 202, 0.12);
  color: var(--accent);
}

@media (max-width: 640px) {
  .site-header__actions {
    display: none;
  }
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  color: var(--fg);
}

.brand:hover,
.brand:focus-visible {
  color: var(--fg);
  text-decoration: none;
}

.brand-name {
  font-weight: 600;
}

.logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: rgba(67, 56, 202, 0.12);
  color: var(--accent);
  font-size: 1.1rem;
}

/* Buttons */
button,
input[type='submit'],
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.825rem 1.6rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: transform var(--transition-base), filter var(--transition-base), box-shadow var(--transition-base);
  box-shadow: var(--shadow-button);
}

button:hover,
button:focus-visible,
input[type='submit']:hover,
input[type='submit']:focus-visible,
.btn:hover,
.btn:focus-visible {
  transform: translateY(-1px);
  filter: brightness(1.02);
  box-shadow: var(--shadow-button-hover);
}

button:active,
input[type='submit']:active,
.btn:active {
  transform: translateY(0);
}

button:disabled,
input[type='submit']:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Form controls */
input,
textarea,
select {
  width: 100%;
  padding: 0.875rem 1.125rem;
  border-radius: 0.75rem;
  border: 1.5px solid rgba(15, 23, 42, 0.08);
  background: var(--surface);
  color: var(--fg);
  font-size: 0.9375rem;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
}

input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--outline);
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

form {
  display: grid;
  gap: 1rem;
}

/* Components */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
}

.success {
  background: var(--success-bg);
  color: var(--success);
  border-radius: var(--radius-sm);
  padding: 1.1rem 1.35rem;
  margin-top: 1.25rem;
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-pill);
  background: rgba(99, 102, 241, 0.08);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.prose {
  font-size: 1rem;
  line-height: 1.75;
}

.prose h1,
.prose h2,
.prose h3 {
  margin-top: 2rem;
}

.prose h1:first-child,
.prose h2:first-child,
.prose h3:first-child {
  margin-top: 0;
}

.prose p + h2,
.prose p + h3 {
  margin-top: 2rem;
}

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