/* ============================================================
   DownTube 웹사이트 공통 스타일
   브랜드: 레드 그라데이션 #FF5A60 → #F4B4B4, 다크 테마
   ============================================================ */

:root {
  --brand: #FF5A60;
  --brand-2: #F4B4B4;
  --bg: #0E0E12;
  --surface: #17171E;
  --surface-2: #1F1F29;
  --border: #2A2A36;
  --text: #F4F4F7;
  --text-dim: #A0A0AE;
  --success: #35C759;
  --radius: 24px;
  --radius-sm: 14px;
  --maxw: 1080px;
  --grad: linear-gradient(135deg, #FF5A60 0%, #F4B4B4 100%);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
header.site {
  position: sticky; top: 0; z-index: 50;
  background: rgba(14, 14, 18, 0.78);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: 20px; }
.brand .logo { width: 36px; height: 36px; border-radius: 11px; display: block; }
.nav-links { display: flex; gap: 28px; align-items: center; }
.nav-links a { color: var(--text-dim); font-weight: 600; font-size: 15px; transition: color .15s; }
.nav-links a:hover { color: var(--text); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 28px; border-radius: 999px;
  font-weight: 700; font-size: 16px; cursor: pointer;
  border: none; transition: transform .12s, box-shadow .2s;
}
.btn-primary { background: var(--grad); color: #1a0d0d; box-shadow: 0 8px 28px rgba(255,90,96,.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 36px rgba(255,90,96,.45); }
.btn-ghost { background: var(--surface-2); color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--surface); }

/* ---------- Hero ---------- */
.hero { padding: 96px 0 72px; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; top: -200px; left: 50%; transform: translateX(-50%);
  width: 720px; height: 720px; border-radius: 50%;
  background: radial-gradient(circle, rgba(255,90,96,.22), transparent 60%);
  filter: blur(40px); z-index: 0;
}
.hero .wrap { position: relative; z-index: 1; text-align: center; }
.hero .logo-big { width: 96px; height: 96px; border-radius: 28px; margin: 0 auto 28px; display: block;
  box-shadow: 0 16px 48px rgba(255,90,96,.4); }
.hero h1 { font-size: clamp(36px, 6vw, 60px); font-weight: 800; letter-spacing: -1.5px; line-height: 1.1; }
.hero h1 .accent { background: var(--grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero p.sub { font-size: clamp(17px, 2.5vw, 21px); color: var(--text-dim); margin: 22px auto 0; max-width: 620px; }
.hero .cta { margin-top: 40px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ---------- Sections ---------- */
section { padding: 72px 0; }
.section-head { text-align: center; margin-bottom: 56px; }
.section-head h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; letter-spacing: -1px; }
.section-head p { color: var(--text-dim); margin-top: 14px; font-size: 17px; }

/* ---------- Feature grid ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 32px 28px; transition: transform .15s, border-color .15s;
}
.card:hover { transform: translateY(-4px); border-color: var(--brand); }
.card .ico {
  width: 52px; height: 52px; border-radius: 15px; display: flex; align-items: center; justify-content: center;
  background: rgba(255,90,96,.14); margin-bottom: 20px;
}
.card .ico svg { width: 28px; height: 28px; stroke: var(--brand); }
.card h3 { font-size: 19px; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--text-dim); font-size: 15px; }

/* ---------- Steps ---------- */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
.step { text-align: center; }
.step .num {
  width: 56px; height: 56px; border-radius: 50%; margin: 0 auto 18px;
  display: flex; align-items: center; justify-content: center;
  font-size: 24px; font-weight: 800; background: var(--grad); color: #1a0d0d;
}
.step h3 { font-size: 18px; margin-bottom: 6px; }
.step p { color: var(--text-dim); font-size: 15px; }

/* ---------- CTA band ---------- */
.cta-band { background: var(--grad); border-radius: 32px; padding: 56px 32px; text-align: center; margin: 24px 0; }
.cta-band h2 { color: #1a0d0d; font-size: clamp(26px, 4vw, 38px); font-weight: 800; letter-spacing: -1px; }
.cta-band p { color: #3a1414; margin: 14px 0 28px; font-size: 17px; font-weight: 500; }
.cta-band .btn-dark { background: #14141a; color: #fff; }
.cta-band .btn-dark:hover { background: #000; }

/* ---------- Footer ---------- */
footer.site { border-top: 1px solid var(--border); padding: 48px 0 64px; margin-top: 40px; }
.foot { display: flex; justify-content: space-between; gap: 28px; flex-wrap: wrap; align-items: flex-start; }
.foot .brand { font-size: 18px; }
.foot-links { display: flex; gap: 24px; flex-wrap: wrap; }
.foot-links a { color: var(--text-dim); font-size: 14px; }
.foot-links a:hover { color: var(--text); }
.copy { color: var(--text-dim); font-size: 13px; margin-top: 28px; }

/* ---------- Legal / document pages ---------- */
.doc { padding: 64px 0; }
.doc .wrap { max-width: 820px; }
.doc h1 { font-size: clamp(30px, 5vw, 44px); font-weight: 800; letter-spacing: -1px; margin-bottom: 8px; }
.doc .updated { color: var(--text-dim); font-size: 14px; margin-bottom: 40px; }
.doc h2 { font-size: 22px; font-weight: 700; margin: 40px 0 14px; padding-top: 14px; border-top: 1px solid var(--border); }
.doc h3 { font-size: 17px; font-weight: 700; margin: 24px 0 8px; color: var(--brand-2); }
.doc p, .doc li { color: #D4D4DE; font-size: 15.5px; }
.doc ul { margin: 12px 0 12px 22px; }
.doc li { margin-bottom: 8px; }
.doc strong { color: var(--text); }
.doc a { color: var(--brand); text-decoration: underline; }
.doc table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14.5px; }
.doc th, .doc td { border: 1px solid var(--border); padding: 10px 12px; text-align: left; vertical-align: top; }
.doc th { background: var(--surface-2); font-weight: 700; }
.doc .note {
  background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm); padding: 16px 20px; margin: 20px 0; color: var(--text-dim); font-size: 14.5px;
}
.back-home { display: inline-flex; align-items: center; gap: 8px; color: var(--text-dim); font-weight: 600; margin-bottom: 32px; font-size: 14px; }
.back-home:hover { color: var(--text); }

@media (max-width: 640px) {
  .nav-links { display: none; }
  section, .hero { padding: 56px 0; }
}