:root {
  color-scheme: dark;
  --bg: #12161d;
  --surface: #1a202a;
  --surface-2: #222a37;
  --line: #2d3848;
  --text: #f0f4f8;
  --muted: #94a3b8;
  --accent: #5a9ec7;
  --accent-soft: #8cc4e8;
  --accent-glow: rgba(90, 158, 199, 0.2);
  --max: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Pretendard, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.wrap {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(18, 22, 29, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.03em;
  text-decoration: none;
  color: var(--text);
}

.brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: cover;
}

.nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav a {
  color: var(--muted);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: color 0.15s ease;
}

.nav a:hover,
.nav a.active {
  color: var(--text);
}

.nav .button {
  min-height: 40px;
  padding: 0 18px;
  font-size: 14px;
}

/* Hero */
.hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 60px;
  min-height: 600px;
  padding: 80px 0 100px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 20px;
  color: var(--accent-soft);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.eyebrow::before {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent);
  content: "";
}

h1, h2, h3, p { margin-top: 0; }

h1 {
  max-width: 720px;
  margin-bottom: 24px;
  font-size: clamp(44px, 5.8vw, 76px);
  line-height: 1.08;
  letter-spacing: -0.055em;
}

.hero-copy {
  max-width: 540px;
  margin-bottom: 36px;
  color: var(--muted);
  font-size: clamp(17px, 1.8vw, 20px);
  line-height: 1.6;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 24px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface-2);
  color: var(--text);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 2px 0 rgba(0,0,0,0.3);
  transition: transform 0.16s ease, background 0.16s ease, border-color 0.16s ease;
  cursor: pointer;
}

.button:hover {
  transform: translateY(-1px);
  background: #2b3546;
  border-color: #3e4d63;
}

.button.primary {
  border-color: #6fb1da;
  background: var(--accent);
  color: #0d1e2b;
  box-shadow: 0 3px 0 #3b7496;
}

.button.primary:hover {
  background: #6eb7e2;
}

/* App Hero Visual / Mockup */
.preview-shell {
  width: min(100%, 420px);
  justify-self: end;
  padding: 24px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 28px;
  background: linear-gradient(145deg, #1d2533, #151a23);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
}

.chat-bubble {
  padding: 16px 20px;
  border-radius: 18px;
  font-size: 14px;
  line-height: 1.5;
  margin-bottom: 14px;
  max-width: 85%;
}

.chat-user {
  background: #2a3547;
  color: #e2e8f0;
  margin-left: auto;
  border-bottom-right-radius: 4px;
}

.chat-ai {
  background: #203646;
  border: 1px solid rgba(90, 158, 199, 0.3);
  color: #e6f3fa;
  margin-right: auto;
  border-bottom-left-radius: 4px;
}

.summary-card-preview {
  margin-top: 18px;
  padding: 18px;
  border-radius: 16px;
  background: rgba(90, 158, 199, 0.08);
  border: 1px dashed rgba(90, 158, 199, 0.35);
}

.summary-card-preview .tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-soft);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.summary-card-preview h4 {
  margin: 0 0 6px;
  font-size: 16px;
  color: #fff;
}

.summary-card-preview p {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.5;
}

/* Sections */
.section {
  padding: 90px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 44px;
}

.section h2 {
  margin-bottom: 0;
  font-size: clamp(32px, 3.8vw, 48px);
  line-height: 1.16;
  letter-spacing: -0.04em;
}

.section-lead {
  max-width: 480px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 16px;
}

/* Features Grid */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  min-height: 220px;
  padding: 32px 28px;
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: 18px;
  background: var(--surface);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
  border-color: rgba(90, 158, 199, 0.3);
  transform: translateY(-2px);
}

.card-number {
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.card h3 {
  margin: 28px 0 12px;
  font-size: 22px;
  letter-spacing: -0.03em;
}

.card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.6;
}

/* Support Panel & Hub */
.support-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 44px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 22px;
  background: var(--surface);
}

.support-panel h2 {
  margin-bottom: 8px;
  font-size: 28px;
}

.support-panel p {
  margin-bottom: 0;
  color: var(--muted);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 32px;
}

.support-card {
  display: block;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface-2);
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s;
}

.support-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.support-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
  color: var(--text);
}

.support-card p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

/* Legal & Document Layout */
.legal-main {
  width: min(calc(100% - 40px), 820px);
  margin: 0 auto;
  padding: 70px 0 120px;
}

.legal-main h1 {
  font-size: clamp(36px, 5vw, 54px);
  margin-bottom: 12px;
}

.legal-meta {
  margin-bottom: 44px;
  color: var(--muted);
  font-size: 15px;
}

.legal-main h2 {
  margin: 48px 0 16px;
  font-size: 24px;
  letter-spacing: -0.03em;
  color: var(--text);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 8px;
}

.legal-main h3 {
  margin: 28px 0 10px;
  font-size: 18px;
  color: var(--accent-soft);
}

.legal-main p,
.legal-main li {
  color: #cbd5e1;
  font-size: 15px;
  line-height: 1.7;
}

.legal-main a {
  color: var(--accent-soft);
  text-decoration: underline;
}

.legal-main ul,
.legal-main ol {
  padding-left: 24px;
  margin-bottom: 20px;
}

.legal-main li {
  margin-bottom: 8px;
}

/* FAQ Accordions */
.faq-item {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item[open] {
  border-color: rgba(90, 158, 199, 0.4);
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 17px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 22px;
  color: var(--accent-soft);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 24px 22px;
  color: #cbd5e1;
  font-size: 15px;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 4px;
  padding-top: 16px;
}

/* Notice List */
.notice-item {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
  margin-bottom: 16px;
}

.notice-date {
  font-size: 13px;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 6px;
}

.notice-item h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.notice-item p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

/* Footer */
.site-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: #0e1217;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 40px;
  padding: 50px 0;
}

.footer-brand {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.footer-copy,
.footer-meta {
  color: var(--muted);
  font-size: 14px;
}

.footer-meta {
  text-align: right;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.15s;
}

.footer-links a:hover {
  color: var(--text);
}

/* Responsive */
@media (max-width: 820px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 48px;
    min-height: auto;
    padding: 60px 0 80px;
  }
  .preview-shell {
    width: 100%;
    max-width: 480px;
    justify-self: start;
  }
  .section {
    padding: 70px 0;
  }
  .section-head,
  .support-panel {
    align-items: flex-start;
    flex-direction: column;
  }
  .features {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .header-inner {
    min-height: 64px;
  }
  .brand {
    font-size: 19px;
  }
  .nav {
    gap: 14px;
  }
  .nav a {
    font-size: 14px;
  }
  .nav .download-btn {
    display: none;
  }
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .footer-meta {
    text-align: left;
  }
  .footer-links {
    justify-content: flex-start;
  }
}