/* =========================================
   Air Design System — japan landing page
   ========================================= */

html {
  scroll-behavior: smooth;
}

/* ── Design Tokens ────────────────────────── */
:root {
  --color-sky-canvas: #426188;
  --color-action-blue: #2b7fff;
  --color-cloud-white: #ffffff;
  --color-charcoal-text: #1b1b1b;
  --color-haze-grey: #f5f5f5;

  --font-serif: 'Noto Serif KR', Georgia, serif;
  --font-sans: 'Inter', 'Noto Sans KR', sans-serif;
}

/* ── Glass Card ───────────────────────────── */
.glass {
  background: rgba(255, 255, 255, 0.13);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 14px;
}

/* ── Ghost Button (white outline on blue bg) */
.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 8px;
  padding: 8px 20px;
  background: transparent;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.15s;
  text-decoration: none;
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #ffffff;
  transform: translateY(-1px);
}

/* ── Action Button (blue outline) ─────────── */
.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  color: #2b7fff;
  border: 1px solid #2b7fff;
  border-radius: 8px;
  padding: 8px 20px;
  background: transparent;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, transform 0.15s;
  text-decoration: none;
}
.btn-action:hover {
  background: #2b7fff;
  color: #ffffff;
  transform: translateY(-1px);
}

/* ── Nav CTA Button (white filled) ───────── */
.btn-cta {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  color: #1b1b1b;
  background: #ffffff;
  border-radius: 8px;
  padding: 7px 18px;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, transform 0.12s, box-shadow 0.15s;
  border: none;
}
.btn-cta:hover {
  background: #e8f0ff;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

/* ── Hero CTA (filled blue) ───────────────── */
.btn-action-filled {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  color: #ffffff;
  background: #2b7fff;
  border: 1px solid #2b7fff;
  border-radius: 8px;
  padding: 10px 24px;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, transform 0.15s, box-shadow 0.15s;
}
.btn-action-filled:hover {
  background: #1a6ee8;
  border-color: #1a6ee8;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(43, 127, 255, 0.45);
}

/* ── Feature Card (light, for Courses/FAQ) ── */
.feature-card {
  background: #ffffff;
  border-radius: 14px;
  padding: 28px;
  color: var(--color-charcoal-text);
}

/* ── Section Label ────────────────────────── */
.section-label {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ── FAQ ──────────────────────────────────── */
.faq-answer {
  transition: max-height 0.3s ease, padding 0.2s ease;
}
.faq-icon {
  transition: transform 0.25s ease;
}
.faq-icon.open {
  transform: rotate(180deg);
}

/* ── Review Marquee ───────────────────────── */
.review-marquee-outer {
  overflow: hidden;
  -webkit-mask-image: linear-gradient(to right, transparent 0%, black 8%, black 92%, transparent 100%);
  mask-image: linear-gradient(to right, transparent 0%, black 8%, black 92%, transparent 100%);
}

.review-marquee-track {
  display: flex;
  gap: 0;
  width: max-content;
  animation: reviewMarquee 36s linear infinite;
}

.review-marquee-track:hover {
  animation-play-state: paused;
}

.review-marquee-item {
  width: 300px;
  flex-shrink: 0;
  margin-right: 16px;
}

@keyframes reviewMarquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* ── Review Card on blue bg ───────────────── */
.review-card {
  background: rgba(255, 255, 255, 0.10);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 14px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* ── Scroll Reveal ────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}


/* ── Lightbox ─────────────────────────────── */
#lightbox {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.85);
  display: none;
  align-items: center;
  justify-content: center;
}
#lightbox.flex {
  display: flex;
}

/* ── Curriculum Tab ───────────────────────── */
.curriculum-tab {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  padding: 6px 16px;
  border-radius: 8px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, color 0.15s;
  border: 1px solid transparent;
}
.curriculum-tab.active {
  background: #1b1b1b;
  color: #ffffff;
  border-color: #1b1b1b;
}
.curriculum-tab:not(.active) {
  background: #ffffff;
  color: #6b7280;
  border-color: #e5e7eb;
}


/* ── Gradient text for hero display ──────── */
.display-text {
  font-family: var(--font-serif);
  font-weight: 900;
  line-height: 0.85;
  color: #ffffff;
  letter-spacing: -0.02em;
}


/* ── Header border on scroll ──────────────── */
#header.scrolled {
  border-bottom-color: rgba(255, 255, 255, 0.12);
  background: rgba(66, 97, 136, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}