:root {
  --navy: #07284a;
  --pine: #0f766e;
  --paper: #f4f0e6;
  --ink: #142033;
}

html {
  scroll-padding-top: 5.5rem;
}

body {
  font-family: "Noto Sans Thai", ui-sans-serif, system-ui, sans-serif;
  text-rendering: optimizeLegibility;
}

h1,
h2,
h3,
h1 span,
.font-display {
  font-family: Kanit, "Noto Sans Thai", sans-serif;
  line-height: 1.45 !important;
}

::selection {
  background: #99f6e4;
  color: var(--navy);
}

:focus-visible {
  outline: 2px solid var(--pine);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 80;
  border-radius: 0.5rem;
  background: white;
  color: var(--navy);
  padding: 0.6rem 1rem;
  font-weight: 600;
}

.skip-link:focus {
  top: 1rem;
}

.hero-panel {
  background:
    radial-gradient(900px 420px at 110% -10%, rgba(15, 157, 138, 0.38), transparent 55%),
    radial-gradient(640px 360px at -10% 120%, rgba(232, 163, 23, 0.18), transparent 50%),
    var(--navy);
}

.hero-preview {
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.97);
  box-shadow: 0 24px 60px rgba(2, 12, 27, 0.35);
}

.book-card {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.45), transparent 42%),
    var(--paper);
  box-shadow: inset 0 0 0 1px #e3d9c8;
}

.book-card [data-correct] {
  border-color: #b42318;
  background: #fff6f5;
  color: #9f1c1c;
  font-weight: 700;
}

.tutor-card [data-correct].is-revealed {
  border-color: var(--pine);
  background: #f0fdfa;
  color: #115e59;
  font-weight: 700;
}

.step-panel {
  display: none;
}

.step-panel.is-current {
  display: block;
}

.step-pip {
  height: 0.35rem;
  flex: 1;
  border-radius: 999px;
  background: #dbe7e5;
}

.step-pip.is-done {
  background: #99f6e4;
}

.step-pip.is-current {
  background: var(--pine);
}

.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;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
}

.nav-toggle .icon-close {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-open {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

@media (max-width: 767px) {
  .site-nav {
    display: none;
    flex-basis: 100%;
    flex-direction: column;
    gap: 0.15rem;
    padding-top: 0.75rem;
  }

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

  .site-nav .nav-link {
    display: block;
    padding: 0.85rem 0.25rem;
  }

  .sticky-cta.is-hidden,
  body.nav-open .sticky-cta {
    visibility: hidden;
    pointer-events: none;
  }
}

@media (min-width: 768px) {
  .site-bar {
    flex-wrap: nowrap;
  }

  .nav-toggle,
  .sticky-cta {
    display: none !important;
  }

  .site-nav {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-left: auto;
  }
}

.faq-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.24s ease;
}

.faq-panel.is-open {
  grid-template-rows: 1fr;
}

.faq-panel > div {
  overflow: hidden;
}

.faq-toggle[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .faq-panel {
    transition: none;
  }
}