:root {
  color-scheme: light dark;
  --bg: #f5f6fa;
  --surface: #ffffff;
  --fg: #16181d;
  --muted: #5d6270;
  --faint: #8a8f9c;
  --line: rgba(22, 24, 29, 0.1);
  --accent: #3d62f5;
  --accent-soft: rgba(61, 98, 245, 0.1);
  --radius: 16px;
  --wrap: 760px;
  font-family: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1116;
    --surface: #181b22;
    --fg: #eef0f5;
    --muted: #a5abb8;
    --faint: #7c8391;
    --line: rgba(238, 240, 245, 0.12);
    --accent: #7b93ff;
    --accent-soft: rgba(123, 147, 255, 0.14);
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-size: 16px;
  line-height: 1.65;
  word-break: keep-all;
  overflow-wrap: anywhere;
}

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

a:hover {
  text-decoration: underline;
}

.skip-link {
  position: absolute;
  left: -9999px;
}

.skip-link:focus {
  left: 16px;
  top: 12px;
  padding: 8px 12px;
  background: var(--surface);
  border-radius: 8px;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 20px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 60px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--fg);
  font-weight: 700;
}

.brand img {
  border-radius: 8px;
}

.nav {
  display: flex;
  gap: 18px;
  font-size: 0.94em;
}

.nav a {
  color: var(--muted);
}

.nav a[aria-current="page"] {
  color: var(--fg);
  font-weight: 600;
}

main {
  padding: 28px 0 64px;
}

.hero {
  padding: 32px 0 20px;
  text-align: center;
}

.hero img {
  border-radius: 28px;
  box-shadow: 0 18px 40px rgba(61, 98, 245, 0.28);
}

.hero h1 {
  margin: 22px 0 8px;
  font-size: clamp(30px, 6vw, 44px);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.lead {
  margin: 0 auto;
  max-width: 560px;
  color: var(--muted);
  font-size: 1.08em;
}

.intro {
  margin: 0;
  color: var(--muted);
  font-size: 1.08em;
}

h1 {
  margin: 12px 0 6px;
  font-size: clamp(28px, 5vw, 36px);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 24px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  background: var(--accent);
  color: #ffffff;
  font-weight: 600;
}

.button.secondary {
  background: var(--accent-soft);
  color: var(--accent);
}

.button:hover {
  text-decoration: none;
  filter: brightness(1.05);
}

section {
  margin-top: 40px;
}

h2 {
  margin: 0 0 14px;
  font-size: 1.45em;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

h3 {
  margin: 22px 0 6px;
  font-size: 1.08em;
}

p {
  margin: 0 0 12px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.tile {
  padding: 18px 18px 16px;
  border-radius: var(--radius);
  background: var(--surface);
}

.tile strong {
  display: block;
  margin-bottom: 4px;
}

.tile span {
  color: var(--muted);
  font-size: 0.94em;
}

.steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  position: relative;
  margin: 0 0 12px;
  padding: 14px 16px 14px 56px;
  border-radius: var(--radius);
  background: var(--surface);
  counter-increment: step;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 14px;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--accent);
  color: #ffffff;
  font-size: 0.85em;
  font-weight: 700;
}

.note {
  padding: 16px 18px;
  border-radius: var(--radius);
  background: var(--accent-soft);
}

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

.doc h2 {
  margin-top: 36px;
  font-size: 1.2em;
}

.doc ul {
  margin: 0 0 12px;
  padding-left: 20px;
}

.doc li {
  margin-bottom: 6px;
}

.meta {
  color: var(--faint);
  font-size: 0.92em;
}

.lang-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 56px 0 8px;
  color: var(--faint);
  font-size: 0.9em;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.lang-divider::before,
.lang-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.demo-video {
  margin: 14px 0 8px;
  border-radius: var(--radius);
  overflow: hidden;
  background: #000000;
}

.demo-video video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
}

.faq details {
  margin-bottom: 10px;
  padding: 14px 18px;
  border-radius: var(--radius);
  background: var(--surface);
}

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

.faq details p {
  margin: 10px 0 0;
  color: var(--muted);
}

footer {
  padding: 28px 0 40px;
  color: var(--faint);
  font-size: 0.9em;
}

footer .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
}

footer nav {
  display: flex;
  gap: 16px;
}

footer a {
  color: var(--muted);
}

@media (max-width: 520px) {
  .nav {
    gap: 14px;
  }

  .nav .optional {
    display: none;
  }
}