/* =========================================================
   Pixel Summit 2026 — shared stylesheet
   Every page links this one file so the design stays consistent.
   ========================================================= */

/* ---------- Design tokens ---------- */
:root {
  /* Colours (all text/background pairs meet WCAG AA 4.5:1 or better) */
  --color-bg: #ffffff;
  --color-surface: #f5f5fa;
  --color-text: #1b1b2f;          /* 16.4:1 on white */
  --color-muted: #4a4a63;         /* 8.6:1 on white  */
  --color-primary: #3b2fc9;       /* 8.1:1 on white  */
  --color-primary-dark: #2a2096;
  --color-on-primary: #ffffff;
  --color-accent: #ffb020;        /* decorative only, never used for text on white */
  --color-border: #d9d9e6;
  --color-success: #126b38;       /* 6.6:1 on white */
  --color-error: #b3261e;         /* 6.5:1 on white */

  /* Type */
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-display: "Space Grotesk", var(--font-body);

  /* Spacing & shape */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2.5rem;
  --space-6: 4rem;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 6px 24px rgba(27, 27, 47, 0.08);
  --max-width: 1120px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  line-height: 1.2;
  margin: 0 0 var(--space-3);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.3rem); }
h3 { font-size: 1.2rem; }

p { margin: 0 0 var(--space-3); }

a {
  color: var(--color-primary);
  text-underline-offset: 3px;
}

a:hover { color: var(--color-primary-dark); }

/* Visible keyboard focus everywhere */
:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* Make the hidden attribute win over display rules like grid/flex */
[hidden] { display: none !important; }

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

/* Skip link: hidden until focused with the keyboard */
.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -100px;
  z-index: 100;
  padding: var(--space-2) var(--space-3);
  background: var(--color-primary);
  color: var(--color-on-primary);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.skip-link:focus { top: var(--space-3); color: var(--color-on-primary); }

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

.section { padding-block: var(--space-6); }
.section--alt { background: var(--color-surface); }

.section-head {
  max-width: 640px;
  margin-bottom: var(--space-5);
}

.eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.lead {
  font-size: 1.15rem;
  color: var(--color-muted);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 44px;              /* comfortable touch target */
  padding: 0.7rem 1.4rem;
  border: 2px solid transparent;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, transform 0.2s;
}

.btn:hover { transform: translateY(-2px); }

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

.btn--primary:hover {
  background: var(--color-primary-dark);
  color: var(--color-on-primary);
}

.btn--ghost {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: transparent;
}

.btn--ghost:hover {
  background: var(--color-primary);
  color: var(--color-on-primary);
}

/* ---------- Header / navigation ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: var(--space-3);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

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

.logo-mark {
  width: 32px;
  height: 32px;
}

.nav-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  cursor: pointer;
}

.nav-toggle-bar,
.nav-toggle-bar::before,
.nav-toggle-bar::after {
  display: block;
  width: 20px;
  height: 2px;
  margin-inline: auto;
  background: currentColor;
  transition: transform 0.25s;
}

.nav-toggle-bar { position: relative; }

.nav-toggle-bar::before,
.nav-toggle-bar::after {
  content: "";
  position: absolute;
  left: 0;
}

.nav-toggle-bar::before { top: -6px; }
.nav-toggle-bar::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bar { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::after { transform: translateY(-6px) rotate(-45deg); }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  display: block;
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  color: var(--color-text);
  font-weight: 500;
  text-decoration: none;
}

.nav-links a:hover { background: var(--color-surface); }

/* Current page, set with aria-current="page" in the HTML */
.nav-links a[aria-current="page"] {
  background: var(--color-primary);
  color: var(--color-on-primary);
}

/* ---------- Page hero (inner pages) ---------- */
.page-hero {
  padding-block: var(--space-6) var(--space-5);
  background:
    radial-gradient(circle at 85% 20%, rgba(255, 176, 32, 0.18), transparent 40%),
    radial-gradient(circle at 10% 80%, rgba(59, 47, 201, 0.12), transparent 45%),
    var(--color-surface);
}

.page-hero .lead { max-width: 640px; }

/* ---------- Home hero ---------- */
.hero {
  padding-block: var(--space-6);
  background:
    radial-gradient(circle at 90% 10%, rgba(255, 176, 32, 0.22), transparent 35%),
    radial-gradient(circle at 0% 100%, rgba(59, 47, 201, 0.14), transparent 45%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: var(--space-5);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-4);
  margin: 0 0 var(--space-4);
  padding: 0;
  list-style: none;
  font-weight: 600;
  color: var(--color-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.hero-art {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* ---------- Countdown ---------- */
.countdown {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  margin: 0;
}

.countdown div {
  padding: var(--space-3);
  text-align: center;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.countdown dt {
  order: 2;
  font-size: 0.85rem;
  color: var(--color-muted);
}

.countdown dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--color-primary);
}

.countdown div { display: flex; flex-direction: column; }

/* ---------- Cards & grids ---------- */
.grid {
  display: grid;
  gap: var(--space-4);
}

.grid--3 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

.card {
  padding: var(--space-4);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card-icon {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  margin-bottom: var(--space-3);
  border-radius: 12px;
  background: rgba(59, 47, 201, 0.1);
  color: var(--color-primary);
  font-size: 1.4rem;
}

.card p:last-child { margin-bottom: 0; }

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-4);
  margin: 0;
  text-align: center;
}

.stats div { display: flex; flex-direction: column-reverse; }

.stats dt { color: var(--color-muted); }

.stats dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--color-primary);
}

/* ---------- Venue / split layout ---------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: var(--space-5);
}

.split img { border-radius: var(--radius); box-shadow: var(--shadow); }

.check-list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-4);
}

.check-list li {
  position: relative;
  padding-left: 1.8rem;
  margin-bottom: var(--space-2);
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  font-weight: 700;
  color: var(--color-success);
}

/* ---------- FAQ (native <details>) ---------- */
.faq details {
  margin-bottom: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.faq summary {
  font-weight: 600;
  cursor: pointer;
}

.faq details p { margin: var(--space-3) 0 0; color: var(--color-muted); }

/* ---------- CTA banner ---------- */
.cta {
  padding: var(--space-5);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: var(--color-on-primary);
  text-align: center;
}

.cta p { color: #e6e4ff; }   /* 11:1 on the gradient's lightest end */

.cta .btn--light {
  background: var(--color-bg);
  color: var(--color-primary);
}

/* ---------- Schedule ---------- */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.tab {
  min-height: 44px;
  padding: 0.55rem 1.2rem;
  border: 2px solid var(--color-primary);
  border-radius: 999px;
  background: var(--color-bg);
  color: var(--color-primary);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

.tab[aria-selected="true"] {
  background: var(--color-primary);
  color: var(--color-on-primary);
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.filter-bar select { width: auto; }

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.session {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--space-3);
  padding: var(--space-4) 0;
  border-top: 1px solid var(--color-border);
}

.session:last-child { border-bottom: 1px solid var(--color-border); }

.session time {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-primary);
}

.session h3 { margin-bottom: var(--space-1); }
.session p { margin: 0; color: var(--color-muted); }

.tag {
  display: inline-block;
  margin-bottom: var(--space-2);
  padding: 0.15rem 0.65rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.tag--talk { background: #ece9ff; border-color: #c9c2ff; }
.tag--workshop { background: #fff1d6; border-color: #ffd98a; }
.tag--break { background: #e3f5ea; border-color: #a9dcbc; }

/* ---------- Speakers ---------- */
.plain-list { list-style: none; padding: 0; margin: 0; }

.speaker {
  height: 100%;
  text-align: center;
}

.speaker img {
  width: 140px;
  height: 140px;
  margin: 0 auto var(--space-3);
  border-radius: 50%;
}

.speaker .role {
  margin-bottom: var(--space-2);
  color: var(--color-muted);
  font-size: 0.95rem;
}

.speaker .topic {
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0;
}

/* ---------- Forms ---------- */
.form {
  display: grid;
  gap: var(--space-4);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.field {
  display: grid;
  gap: var(--space-1);
}

.field label,
fieldset legend {
  font-weight: 600;
}

.required { color: var(--color-error); }

.hint {
  font-size: 0.9rem;
  color: var(--color-muted);
}

input,
select,
textarea {
  width: 100%;
  min-height: 44px;
  padding: 0.65rem 0.85rem;
  border: 2px solid #8a8aa3;   /* 3.4:1 non-text contrast on white */
  border-radius: var(--radius-sm);
  font: inherit;
  color: var(--color-text);
  background: var(--color-bg);
}

textarea { min-height: 120px; resize: vertical; }

input:focus,
select:focus,
textarea:focus {
  border-color: var(--color-primary);
}

input[aria-invalid="true"],
select[aria-invalid="true"],
textarea[aria-invalid="true"] {
  border-color: var(--color-error);
}

.error-msg {
  min-height: 1.2em;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-error);
}

fieldset {
  margin: 0;
  padding: var(--space-3) var(--space-4) var(--space-4);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.choice {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.choice input {
  width: 20px;
  height: 20px;
  min-height: 0;
  accent-color: var(--color-primary);
}

.form-status {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.form-status:empty { display: none; }

.form-status--success {
  background: #e3f5ea;
  color: var(--color-success);
  border: 1px solid #a9dcbc;
}

.form-status--error {
  background: #fde8e7;
  color: var(--color-error);
  border: 1px solid #f3b4b0;
}

.ticket-list { display: grid; gap: var(--space-3); }

.ticket-list .card h3 { margin-bottom: var(--space-1); }

.price {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 0;
}

.register-layout {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: var(--space-5);
  align-items: start;
}

/* ---------- Footer ---------- */
.site-footer {
  padding-block: var(--space-5);
  background: var(--color-text);
  color: #d4d4e4;   /* 11.8:1 on the footer background */
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-5);
}

.site-footer h2 {
  font-size: 1rem;
  color: #ffffff;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-footer li { margin-bottom: var(--space-2); }

.site-footer a { color: #ffffff; }
.site-footer a:hover { color: var(--color-accent); }

.footer-bottom {
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  border-top: 1px solid #3a3a55;
  font-size: 0.9rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; align-items: center; }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-3);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow);
    display: none;
  }

  .nav-links.is-open { display: flex; }

  .nav-links a { padding: 0.8rem 1rem; }

  .hero-grid,
  .split,
  .register-layout,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-art { order: -1; }
}

@media (max-width: 560px) {
  .section { padding-block: var(--space-5); }
  .form-row { grid-template-columns: 1fr; }
  .countdown { grid-template-columns: repeat(2, 1fr); }
  .session { grid-template-columns: 1fr; gap: var(--space-1); }
}

/* Respect users who prefer less motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }
}