/* Light is the default palette; today's dark palette is the single override
   block below. `www/js/theme.js` — primed by the inline bootstrap in
   index.html <head> — sets `data-theme` on <html> before first paint. */
:root {
  color-scheme: light;
  --color-bg: #ffffff;
  --color-surface: #f9f9f7;
  --color-surface-alt: #f2f1ec;
  --color-ink: #171717;
  --color-ink-muted: #5f5f5a;
  --color-accent: #9a5b00;
  --color-accent-fill: #f8ac35;
  --color-on-accent-fill: #14121f;
  --color-accent-dark: #d9901f;
  --color-accent-soft: rgba(154, 91, 0, 0.1);
  --color-border: rgba(0, 0, 0, 0.12);
  --color-header-bg: rgba(255, 255, 255, 0.86);
  --color-backdrop: rgba(23, 23, 23, 0.45);
  --color-shadow: rgba(23, 23, 23, 0.14);
  --color-success: #0f7a58;
  --color-error: #b3261e;
  --max-width: 1120px;
  --radius: 14px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --color-bg: #190f22;
  --color-surface: #1a1830;
  --color-surface-alt: #201d3a;
  --color-ink: #f4f2ec;
  --color-ink-muted: #a9a4c0;
  --color-accent: #f8ac35;
  --color-accent-fill: #f8ac35;
  --color-on-accent-fill: #14121f;
  --color-accent-dark: #d9901f;
  --color-accent-soft: rgba(248, 172, 53, 0.14);
  --color-border: rgba(255, 255, 255, 0.09);
  --color-header-bg: rgba(25, 15, 34, 0.86);
  --color-backdrop: rgba(8, 7, 14, 0.72);
  --color-shadow: rgba(0, 0, 0, 0.65);
  --color-success: #6fe0b8;
  --color-error: #f0876f;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family:
    "Segoe UI",
    system-ui,
    -apple-system,
    Roboto,
    Helvetica,
    Arial,
    sans-serif;
  color: var(--color-ink);
  background: var(--color-bg);
  overflow-x: hidden;
}

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

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header / nav */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--color-header-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  position: relative;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: space-between;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-ink);
  text-decoration: none;
}

.nav-logo {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.nav-menu {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: inline-block;
  padding: 8px 14px;
  color: var(--color-ink);
  text-decoration: none;
  border-radius: 999px;
  font-weight: 500;
}

.nav-link:hover,
.nav-link-active {
  background: var(--color-accent-soft);
  color: var(--color-accent);
}

.nav-link-cta {
  background: var(--color-accent-fill);
  color: var(--color-on-accent-fill);
  font-weight: 700;
}

.nav-link-cta:hover {
  background: var(--color-accent-dark);
  color: var(--color-on-accent-fill);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
}

.nav-toggle-bar {
  width: 22px;
  height: 2px;
  background: var(--color-ink);
  display: block;
}

/* Theme switch */

.theme-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  flex: 0 0 auto;
  padding: 3px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-surface-alt);
}

.theme-option {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 26px;
  padding: 0;
  border: none;
  border-radius: 999px;
  background: none;
  color: var(--color-ink-muted);
  cursor: pointer;
}

.theme-option svg {
  display: block;
  width: 15px;
  height: 15px;
}

.theme-option:hover {
  color: var(--color-ink);
}

.theme-option[aria-pressed="true"] {
  background: var(--color-accent-fill);
  color: var(--color-on-accent-fill);
}

.theme-option:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Sections */

.section {
  padding: 88px 0;
}

.section-home {
  padding-top: 72px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-accent);
  margin: 0 0 12px;
}

h1 {
  font-size: clamp(2rem, 4vw, 3.25rem);
  line-height: 1.1;
  margin: 0 0 20px;
  color: var(--color-ink);
  max-width: 18ch;
}

h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  margin: 0 0 16px;
  color: var(--color-ink);
}

.lede,
.section-intro {
  font-size: 1.1rem;
  color: var(--color-ink-muted);
  max-width: 62ch;
  line-height: 1.6;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 32px;
}

.button {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
}

.button-primary {
  background: var(--color-accent-fill);
  color: var(--color-on-accent-fill);
}

.button-primary:hover {
  background: var(--color-accent-dark);
}

.button-secondary {
  background: transparent;
  color: var(--color-ink);
  border: 1px solid var(--color-border);
}

.button-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* Features */

.section-features {
  background: var(--color-surface);
}

.module-core {
  margin-top: 40px;
  padding: 32px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, #5a3268 0%, #3d2247 60%, #2e1a38 100%);
  color: #fff;
}

.module-core-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.16);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.module-core-name {
  margin: 16px 0 8px;
  font-size: 1.6rem;
}

.module-core-tagline {
  margin: 0;
  max-width: 68ch;
  opacity: 0.92;
  line-height: 1.6;
}

.module-group {
  margin-top: 48px;
}

.module-group-heading {
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  margin: 0 0 16px;
}

.module-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.module-card {
  --card-accent: var(--color-accent);
  padding: 24px;
  padding-top: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  border-top: 3px solid var(--card-accent, var(--color-border));
  background: var(--color-surface-alt);
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease,
    border-color 0.15s ease;
}

.module-card:hover {
  transform: translateY(-3px);
  border-color: var(--card-accent, var(--color-border));
  box-shadow: 0 14px 28px -18px var(--color-shadow);
}

.module-card-name {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--color-ink);
}

.module-card-tagline {
  margin: 0 0 16px;
  font-size: 0.95rem;
  color: var(--color-ink-muted);
  line-height: 1.55;
}

/* Trust layer: a visibly different, premium-styled card that highlights
   the compliance and signer assurance features built into Cosign. */
.module-card-premium {
  border: 1px solid var(--color-accent);
  background: linear-gradient(
    160deg,
    rgba(248, 172, 53, 0.18) 0%,
    var(--color-surface-alt) 60%
  );
  box-shadow:
    0 0 0 1px rgba(248, 172, 53, 0.28),
    0 20px 40px -22px rgba(248, 172, 53, 0.45);
}

.module-card-premium:hover {
  transform: translateY(-3px);
  border-color: var(--color-accent);
  box-shadow:
    0 0 0 1px var(--color-accent),
    0 24px 44px -20px rgba(248, 172, 53, 0.55);
}

.module-card-premium-badge {
  display: inline-block;
  margin-bottom: 10px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--color-accent-fill);
  color: var(--color-on-accent-fill);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.03em;
}

.billing-section {
  margin-top: 56px;
}

.billing-section-musician {
  position: relative;
  margin-top: 64px;
  padding: 32px;
  border-radius: var(--radius);
  border: 1.5px solid var(--color-accent);
  background:
    radial-gradient(
      circle at 0% 0%,
      rgba(248, 172, 53, 0.16) 0%,
      transparent 55%
    ),
    var(--color-surface-alt);
  box-shadow:
    0 0 0 1px rgba(248, 172, 53, 0.15),
    0 24px 56px -28px rgba(248, 172, 53, 0.5);
}

.billing-section-musician .module-group {
  margin-top: 0;
}

.premium-eyebrow {
  display: inline-block;
  margin: 0 0 10px;
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

.billing-heading {
  margin: 0 0 8px;
  font-size: 1.3rem;
  color: var(--color-ink);
}

.billing-intro {
  margin: 0 0 8px;
  max-width: 62ch;
  color: var(--color-ink-muted);
  line-height: 1.6;
}

/* Support */

.support-cards {
  margin-top: 32px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.support-card {
  padding: 28px;
  border-radius: var(--radius);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}

.support-card h3 {
  margin: 0 0 8px;
  color: var(--color-ink);
}

.link {
  display: inline-block;
  margin-right: 16px;
  color: var(--color-accent);
  font-weight: 600;
  text-decoration: none;
}

.link:hover {
  text-decoration: underline;
}

.link-button {
  display: inline-block;
  margin-top: 8px;
  background: none;
  border: none;
  padding: 0;
  font: inherit;
  cursor: pointer;
}

.support-general {
  margin-top: 28px;
  color: var(--color-ink-muted);
}

/* Contact / apply modal */

.contact-modal {
  border: none;
  border-radius: var(--radius);
  padding: 0;
  background: var(--color-surface);
  color: var(--color-ink);
  width: min(480px, 92vw);
}

.contact-modal::backdrop {
  background: var(--color-backdrop);
  backdrop-filter: blur(2px);
}

.contact-form {
  position: relative;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-form h3 {
  margin: 0;
  padding-right: 24px;
  color: var(--color-ink);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  color: var(--color-ink-muted);
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
}

.modal-close:hover {
  color: var(--color-ink);
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.9rem;
  color: var(--color-ink-muted);
}

.field input,
.field select,
.field textarea {
  font: inherit;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-ink);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}

.contact-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  margin-top: 4px;
}

.contact-status {
  margin: 0;
  font-size: 0.9rem;
  min-height: 1.2em;
  color: var(--color-ink-muted);
}

.contact-status-success {
  color: var(--color-success);
}

.contact-status-error {
  color: var(--color-error);
}

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

/* Footer */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
  color: var(--color-ink-muted);
  font-size: 0.9rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.footer-logo {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  opacity: 0.85;
}

.footer-link {
  color: var(--color-ink-muted);
  text-decoration: none;
  font-weight: 600;
}

.footer-link:hover {
  color: var(--color-accent);
}

/* Mobile nav */

@media (max-width: 768px) {
  .nav {
    padding: 14px 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.2s ease;
  }

  .nav-menu.nav-menu-open {
    max-height: 320px;
  }

  .nav-menu li {
    width: 100%;
  }

  .nav-link {
    width: 100%;
    border-radius: 0;
    padding: 14px 24px;
  }

  .section {
    padding: 56px 0;
  }
}

/* Narrow phones: keep the theme switch, brand and hamburger on one line. */

@media (max-width: 420px) {
  .nav-brand {
    font-size: 1.05rem;
  }

  .theme-option {
    width: 28px;
  }
}

/* Colour transitions are a progressive enhancement: visitors who ask for
   reduced motion get an instant palette swap instead. */

@media (prefers-reduced-motion: no-preference) {
  body,
  .site-header,
  .nav-link,
  .theme-switch,
  .theme-option {
    transition:
      background-color 0.2s ease,
      border-color 0.2s ease,
      color 0.2s ease;
  }
}