:root {
  --bg: #0f1115;
  --bg-elev: #161a22;
  --border: #232a36;
  --text: #e7ecf3;
  --muted: #8a93a6;
  --accent: #3d9e92;
  --accent-hover: #52b5a8;
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Pretendard",
               "Noto Sans KR", Roboto, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

.hero {
  text-align: center;
  padding: 72px 20px 56px;
  background:
    radial-gradient(circle at 50% 0%, rgba(61, 158, 146, 0.2), transparent 60%),
    linear-gradient(180deg, #152420 0%, var(--bg) 100%);
}

.hero-desc {
  max-width: 520px;
  margin: 0 auto 28px;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.65;
}

.logo {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  object-fit: cover;
  border: 1px solid var(--border);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
}

.hero h1 {
  font-size: 2.4rem;
  margin: 20px 0 6px;
  letter-spacing: -0.02em;
}

.tagline {
  color: var(--muted);
  margin: 0 0 32px;
  font-size: 1.05rem;
}

.cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  border-radius: 999px;
  text-decoration: none;
  box-shadow: 0 10px 28px rgba(61, 158, 146, 0.4);
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}
.cta:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(61, 158, 146, 0.5);
}
.cta:active { transform: translateY(0); }

.version {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 14px;
}

main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

section {
  padding: 56px 0;
  border-bottom: 1px solid var(--border);
}
section:last-of-type { border-bottom: none; }

section h2 {
  font-size: 1.45rem;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}

.section-lead {
  color: var(--muted);
  margin: 0 0 28px;
  font-size: 0.98rem;
}

.screen-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 14px;
}

.screen-card {
  margin: 0;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.screen-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
}
.screen-img {
  aspect-ratio: 9 / 19;
  background: #0a0c10;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  overflow: hidden;
}
.screen-img img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
}
.screen-card--contain .screen-img {
  align-items: center;
}
.screen-card--contain .screen-img img {
  object-fit: contain;
  object-position: center;
}
.screen-card figcaption {
  padding: 10px 8px 12px;
  text-align: center;
}
.screen-card strong {
  display: block;
  font-size: 0.88rem;
  margin-bottom: 4px;
}
.screen-card span {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
  line-height: 1.35;
}

@media (max-width: 900px) {
  .screen-grid {
    display: flex;
    flex-wrap: nowrap;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 8px;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
  }
  .screen-card {
    flex: 0 0 38vw;
    min-width: 140px;
    max-width: 200px;
    scroll-snap-align: start;
  }
}

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}
.feature-list li {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.feature-list strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 6px;
}
.feature-list p {
  color: var(--muted);
  margin: 0;
  font-size: 0.95rem;
}

.privacy-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}
.privacy-list li {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.privacy-list strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 6px;
}
.privacy-list p {
  color: var(--muted);
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.55;
}
.privacy-list code {
  font-family: ui-monospace, "SF Mono", Consolas, monospace;
  font-size: 0.85em;
  color: var(--accent);
}

.guide ol {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px 20px 44px;
  margin: 0;
}
.guide li { margin-bottom: 10px; }
.guide li:last-child { margin-bottom: 0; }
.guide small {
  display: block;
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 4px;
}

.qr {
  text-align: center;
}
.qr-desc { color: var(--muted); margin-bottom: 20px; }

.qr-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.qr-box {
  display: block;
  padding: 14px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  line-height: 0;
}
.qr-box img,
.qr-box canvas {
  display: block;
}
.link {
  display: inline-block;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  padding: 10px 18px;
  border-radius: 999px;
  color: var(--accent);
  font-family: ui-monospace, "SF Mono", Consolas, monospace;
  font-size: 0.95rem;
  user-select: all;
}

footer {
  text-align: center;
  color: var(--muted);
  padding: 32px 20px 48px;
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 480px) {
  .hero { padding: 56px 16px 40px; }
  .hero h1 { font-size: 2rem; }
  .cta { padding: 13px 28px; font-size: 1rem; }
  section { padding: 44px 0; }
}