/* ==============================================
   채널원 (CHANNELONE) — Landing Design System
   ============================================== */

:root {
  /* Paper & ink */
  --paper: #f7f6f1;
  --paper-2: #ffffff;
  --paper-warm: #fbfaf5;
  --ink: #0d1a16;
  --ink-2: #1a2b25;
  --ink-soft: #4a5b54;
  --ink-mute: #7a8a83;
  --line: #e2ded0;
  --line-soft: #ece9dd;

  /* Brand */
  --teal-deep: #0b4d3d;
  --teal: #0f6e56;
  --teal-bright: #1ba879;
  --teal-tint: #e7f3ee;
  --teal-tint-2: #d5ebe1;

  /* Accents */
  --coral: #d85a30;
  --coral-soft: #e8845f;
  --coral-tint: #fbeae1;
  --amber: #e5a637;
  --amber-tint: #fbf1dc;

  /* Kakao */
  --kakao: #f7dd3f;
  --kakao-ink: #3a1d1d;

  /* Utility */
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --shadow-1: 0 1px 2px rgba(13,26,22,.04), 0 4px 12px rgba(13,26,22,.04);
  --shadow-2: 0 4px 12px rgba(13,26,22,.06), 0 16px 40px rgba(13,26,22,.08);
  --shadow-3: 0 24px 60px rgba(13,26,22,.12);
  --ease: cubic-bezier(.2,.7,.2,1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'Pretendard', -apple-system, 'Apple SD Gothic Neo', BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  word-break: keep-all;
  overflow-wrap: break-word;
}
h1, h2, h3, h4, p, li, span, div, button, a { word-break: keep-all; overflow-wrap: break-word; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* Layout */
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 32px; }
.wrap-narrow { max-width: 880px; margin: 0 auto; padding: 0 32px; }
section { padding: 120px 0; position: relative; }
@media (max-width: 720px) {
  section { padding: 72px 0; }
  .wrap, .wrap-narrow { padding: 0 20px; }
}

/* Type */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase;
  color: var(--teal); padding: 6px 12px;
  background: var(--teal-tint); border-radius: 999px;
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: 999px; background: var(--teal-bright); box-shadow: 0 0 0 4px rgba(27,168,121,.15); }
h1, h2, h3, h4 { font-family: inherit; font-weight: 700; letter-spacing: -0.02em; line-height: 1.2; color: var(--ink); }
h1 { font-size: clamp(34px, 5.2vw, 64px); letter-spacing: -0.035em; line-height: 1.15; }
h2 { font-size: clamp(28px, 3.8vw, 44px); letter-spacing: -0.025em; line-height: 1.2; }
h3 { font-size: clamp(20px, 2vw, 26px); }
h4 { font-size: 18px; }
p { color: var(--ink-soft); }
.lede { font-size: clamp(17px, 1.4vw, 20px); color: var(--ink-soft); line-height: 1.55; }
.mono { font-family: ui-monospace, 'SF Mono', 'Noto Sans Mono CJK KR', monospace; }

/* Responsive line-break: creates a line break on wider screens, space on mobile */
.lg-only { display: inline; }
.lg-only::before { content: '\A'; white-space: pre; }
@media (max-width: 720px) {
  .lg-only::before { content: ' '; white-space: normal; }
}

/* Non-breaking phrase - keeps a Korean phrase together */
.nb { white-space: nowrap; }
@media (max-width: 480px) { .nb { white-space: normal; } }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 22px; border-radius: 12px; font-weight: 600; font-size: 15px;
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), background .2s;
}
.btn-primary {
  background: var(--ink); color: #fff;
}
.btn-primary:hover { background: var(--teal-deep); transform: translateY(-1px); box-shadow: var(--shadow-2); }
.btn-secondary {
  background: transparent; color: var(--ink);
  box-shadow: inset 0 0 0 1.5px var(--ink);
}
.btn-secondary:hover { background: var(--ink); color: #fff; }
.btn-kakao {
  background: var(--kakao); color: var(--kakao-ink);
}
.btn-kakao:hover { transform: translateY(-1px); box-shadow: var(--shadow-2); }

/* Card */
.card {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s;
}
.card:hover { border-color: var(--teal-tint-2); box-shadow: var(--shadow-2); transform: translateY(-2px); }

/* Section header */
.sec-head { max-width: 720px; margin-bottom: 56px; }
.sec-head p { margin-top: 16px; }
.sec-head.center { margin-left: auto; margin-right: auto; text-align: center; }

/* Reveal animation (IntersectionObserver) */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.in { opacity: 1; transform: translateY(0); }
.reveal.d1 { transition-delay: .08s; }
.reveal.d2 { transition-delay: .16s; }
.reveal.d3 { transition-delay: .24s; }
.reveal.d4 { transition-delay: .32s; }
.reveal.d5 { transition-delay: .40s; }

/* Nav */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 0;
  transition: background .3s, backdrop-filter .3s, box-shadow .3s;
}
.nav.scrolled {
  background: rgba(247,246,241,.85);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--line-soft);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -0.01em; font-size: 17px; }
.brand-mark {
  width: 32px; height: 32px; border-radius: 10px;
  background: #fff;
  display: grid; place-items: center;
  box-shadow: 0 2px 8px rgba(13,26,22,.08), inset 0 0 0 1px var(--line);
  overflow: hidden;
}
.brand-mark svg { width: 100%; height: 100%; }
.brand-mark.dark { background: transparent; box-shadow: none; }
.brand-mark.dark svg .lm-outer { stroke: rgba(255,255,255,.25); }
.brand-mark.dark svg .lm-node { fill: rgba(255,255,255,.7); }
.brand-mark.dark svg .lm-hub { fill: var(--teal-bright); }
.brand-mark.dark svg .lm-line { stroke: var(--teal-bright); }
.nav-cta { display: inline-flex; align-items: center; gap: 8px; padding: 10px 18px; background: var(--ink); color: #fff; border-radius: 10px; font-weight: 600; font-size: 14px; }
.nav-cta:hover { background: var(--teal-deep); }

.nav-tabs {
  display: flex; gap: 4px;
  background: rgba(13,26,22,.04); border-radius: 999px; padding: 4px;
}
.nav-tab {
  padding: 8px 16px; border-radius: 999px;
  font-size: 13px; font-weight: 600; color: var(--ink-soft);
  transition: all .2s;
}
.nav-tab:hover { color: var(--ink); }
.nav-tab.active { background: #fff; color: var(--ink); box-shadow: 0 1px 3px rgba(13,26,22,.08); }
@media (max-width: 720px) {
  .nav-tabs { display: none; }
}

/* Footer */
.footer {
  padding: 60px 0 40px;
  border-top: 1px solid var(--line);
  color: var(--ink-mute);
  font-size: 14px;
}
.footer .row { display: flex; justify-content: space-between; align-items: flex-start; gap: 40px; flex-wrap: wrap; }