:root {
  --bg: #ffffff;
  --fg: #0b0d10;
  --muted: #5b6470;
  --accent: #ff6b35;
  --card: #f6f7f9;
  --border: #e7eaee;
  --max: 1100px;
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0d10;
    --fg: #f1f3f5;
    --muted: #9aa3ad;
    --accent: #ff8a5b;
    --card: #15181c;
    --border: #23272d;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Pretendard Variable",
        "Noto Sans CJK KR", "Noto Sans CJK JP", "Noto Sans CJK SC",
        "Noto Sans Devanagari", "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 12px 20px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-size: 18px; }
.brand img { border-radius: 8px; }
.site-nav { display: flex; align-items: center; gap: 18px; }
.site-nav a { text-decoration: none; color: var(--muted); font-size: 14px; }
.site-nav a:hover { color: var(--fg); }
.lang-switcher select {
  background: transparent; color: var(--fg);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 6px 10px; font-size: 14px; cursor: pointer;
}

/* Sections */
main { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
section { padding: 64px 0; border-bottom: 1px solid var(--border); }
section:last-of-type { border-bottom: none; }
h1, h2, h3 { letter-spacing: -0.02em; line-height: 1.15; margin: 0 0 16px; }
h1 { font-size: clamp(32px, 5vw, 56px); font-weight: 800; }
h2 { font-size: clamp(24px, 3vw, 36px); font-weight: 700; }
h3 { font-size: 18px; font-weight: 600; }
p { margin: 0 0 14px; color: var(--muted); }
.what p, .hero .tagline { color: var(--fg); font-size: 18px; }

/* Hero */
.hero { text-align: center; padding-top: 80px; }
.hero .tagline { max-width: 620px; margin: 0 auto 28px; font-size: 18px; }
.hero-cta { display: inline-flex; gap: 12px; align-items: center; flex-wrap: wrap; justify-content: center; }
.app-store-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--fg); color: var(--bg);
  padding: 12px 18px; border-radius: 12px;
  text-decoration: none; font-weight: 600;
}
.app-store-badge:hover { transform: translateY(-1px); }
.secondary-cta {
  display: inline-flex; align-items: center;
  padding: 12px 18px; border-radius: 12px;
  border: 1px solid var(--border); text-decoration: none; color: var(--fg);
}

/* What */
.what { max-width: 760px; margin: 0 auto; text-align: center; }
.what p { font-size: 17px; }

/* Features */
.feature-grid {
  display: grid; gap: 16px;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) { .feature-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 960px) { .feature-grid { grid-template-columns: 1fr 1fr 1fr; } }
.feature-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px;
}
.feature-card h3 { margin-bottom: 6px; }
.feature-card p { margin: 0; font-size: 15px; }

/* Screenshots */
.screenshot-row {
  display: flex; gap: 16px; overflow-x: auto; padding: 4px 0 16px;
  scroll-snap-type: x mandatory;
}
.screenshot-row img {
  flex: 0 0 auto; width: 240px; border-radius: 24px;
  scroll-snap-align: center; border: 1px solid var(--border);
}
@media (min-width: 640px) { .screenshot-row img { width: 300px; } }

/* FAQ */
.faq { max-width: 760px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
.faq-item summary {
  cursor: pointer; font-weight: 600; padding: 4px 0;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; float: right; transition: transform .2s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { margin: 8px 0 0; }

/* Download */
.download { text-align: center; }
.download .app-store-badge { transform: scale(1.05); margin-top: 10px; }
/* Block-level flex so this wraps below the App Store badge, and
   column-stacked so the "다른 언어로 보기" label sits ABOVE the dropdown
   instead of sticking to it inline. */
.other-langs { margin-top: 28px; display: flex; flex-direction: column; align-items: center; gap: 10px; }

/* Footer */
.site-footer {
  max-width: var(--max); margin: 0 auto;
  padding: 28px 20px 60px;
  color: var(--muted); font-size: 13px;
  display: flex; flex-wrap: wrap; gap: 12px; align-items: center;
}
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--fg); }

/* Responsive header */
@media (max-width: 540px) {
  .site-nav a:not(.lang-switcher) { display: none; }
}

/* Keyboard focus — visible ring on every interactive surface. Uses
   currentColor + outline-offset so it adapts to both light and dark themes. */
.brand:focus-visible,
.site-nav a:focus-visible,
.app-store-badge:focus-visible,
.secondary-cta:focus-visible,
.lang-switcher select:focus-visible,
.faq-item summary:focus-visible,
.site-footer a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}