/* 아띠 (Atti) — 공통 디자인 시스템 */

:root {
  --bg: #fdfbf7;
  --bg-soft: #f6f0e6;
  --surface: #ffffff;
  --ink: #1f1b16;
  --ink-soft: #5a5149;
  --ink-mute: #8a8178;
  --line: #ece4d6;
  --terracotta: #e07856;
  --terracotta-dark: #c96140;
  --ink-blue: #2c4a6e;
  --ink-blue-dark: #1d3450;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 2px rgba(31, 27, 22, 0.04), 0 2px 8px rgba(31, 27, 22, 0.04);
  --shadow-md: 0 4px 12px rgba(31, 27, 22, 0.06), 0 16px 40px rgba(31, 27, 22, 0.06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Apple SD Gothic Neo', sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

img { max-width: 100%; display: block; }

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 상단 네비 */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(253, 251, 247, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.nav-brand:hover { text-decoration: none; }
.nav-brand .dot { color: var(--terracotta); }
.nav-links { display: flex; gap: 24px; }
.nav-links a {
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 500;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }

/* 버튼 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
  border: none;
  cursor: pointer;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
  background: var(--ink);
  color: #fff;
}
.btn-primary:hover { background: #000; box-shadow: var(--shadow-sm); }
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn-ghost:hover { background: var(--bg-soft); }

/* 섹션 공통 */
section { padding: 80px 0; }
.section-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 12px;
  text-align: center;
}
.section-sub {
  font-size: 16px;
  color: var(--ink-mute);
  text-align: center;
  margin-bottom: 48px;
}

/* 푸터 */
.footer {
  border-top: 1px solid var(--line);
  background: var(--bg);
  padding: 40px 24px;
  text-align: center;
}
.footer-links { margin-bottom: 12px; }
.footer-links a {
  font-size: 14px;
  margin: 0 12px;
  color: var(--ink-mute);
}
.footer-links a:hover { color: var(--ink); }
.footer-copy {
  font-size: 13px;
  color: var(--ink-mute);
}

/* 문서 페이지 (약관, 지원) */
.doc {
  padding: 60px 0 80px;
}
.doc h1 {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}
.doc .app-label {
  font-size: 14px;
  color: var(--ink-mute);
  margin-bottom: 40px;
}
.doc h2 {
  font-size: 20px;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 14px;
  color: var(--ink);
}
.doc p, .doc li {
  font-size: 15px;
  color: var(--ink-soft);
  margin-bottom: 10px;
}
.doc ul { padding-left: 20px; margin-bottom: 16px; }
.doc .updated {
  font-size: 13px;
  color: var(--ink-mute);
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  text-align: center;
}

@media (max-width: 640px) {
  section { padding: 56px 0; }
  .section-title { font-size: 24px; }
  .doc h1 { font-size: 26px; }
  .nav-links { gap: 16px; }
}