/* ============================================================
   shared.css — 강의 허브 공통 디자인 토큰 / 공통 컴포넌트
   기존 체험도구(lecture-02-체험/styles.css)의 :root 토큰을 그대로 재사용한다.
   Home과 Experience가 같은 사이트로 느껴지도록 여기 값만 단일 출처로 관리한다.
   ============================================================ */

:root {
  color-scheme: light;
  --ink: #0b1220;
  --muted: #5e6a7d;
  --line: #dce3ee;
  --panel: #ffffff;
  --canvas: #f4f7fb;
  --primary: #2563eb;
  --primary-deep: #1d4ed8;
  --primary-soft: #eaf1ff;
  --success: #0f9f72;
  --success-soft: #e8f8f2;
  --warning: #c26a11;
  --warning-soft: #fff5e8;
  --shadow: 0 20px 55px rgba(11, 18, 32, 0.10);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 15% -5%, rgba(37, 99, 235, .12), transparent 28rem),
    var(--canvas);
  color: var(--ink);
  font-family: Inter, Pretendard, "Noto Sans KR", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button, input, textarea, select { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }

/* Focus 상태는 기존 체험도구와 동일한 강도를 유지한다. */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 3px solid rgba(37, 99, 235, .25);
  outline-offset: 2px;
  border-radius: 6px;
}

/* ------------------------------------------------------------
   Layout
   ------------------------------------------------------------ */

/* PC/프로젝터 최대 폭 1120px, 모바일 좌우 여백 14px 수준 */
.shell {
  width: min(1120px, calc(100% - 28px));
  margin: 0 auto;
}

@media (min-width: 640px) {
  .shell { width: min(1120px, calc(100% - 40px)); }
}

/* ------------------------------------------------------------
   Thin Header
   ------------------------------------------------------------ */

.site-header {
  border-bottom: 1px solid rgba(220, 227, 238, .8);
  background: rgba(255, 255, 255, .62);
  backdrop-filter: saturate(150%) blur(8px);
}

.site-header .shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 58px;
  padding: 10px 0;
}

.brand {
  color: var(--ink);
  font-size: .82rem;
  font-weight: 900;
  letter-spacing: .12em;
  text-decoration: none;
  white-space: nowrap;
}
.brand:hover { color: var(--primary); }

.header-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.header-link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 13px;
  border-radius: 10px;
  color: #475569;
  font-size: .88rem;
  font-weight: 800;
  text-decoration: none;
  transition: background .15s ease, color .15s ease;
}
.header-link:hover { background: var(--primary-soft); color: var(--primary); }

/* 모바일에서는 상단 메뉴를 더 단순하게 — 자료 하나만 남긴다.
   체험은 Hero의 Primary CTA가 담당하므로 상단에 중복 노출하지 않는다. */
.header-link.pc-only { display: none; }
.label-short { display: inline; }
.label-full { display: none; }

@media (min-width: 720px) {
  .brand { font-size: .9rem; }
  .header-link.pc-only { display: inline-flex; }
  .label-short { display: none; }
  .label-full { display: inline; }
}

/* ------------------------------------------------------------
   Typography 공통
   ------------------------------------------------------------ */

.eyebrow {
  color: var(--primary);
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .13em;
}

/* ------------------------------------------------------------
   Buttons
   ------------------------------------------------------------ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 54px;
  padding: 15px 26px;
  border: 0;
  border-radius: 12px;
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -.01em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .15s ease, background .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 10px 22px rgba(37, 99, 235, .24);
}
.btn-primary:hover { background: var(--primary-deep); }

.btn-secondary {
  border: 1px solid var(--line);
  background: #fff;
  color: #475569;
}
.btn-secondary:hover { border-color: #b9c9e4; background: #f8fafd; }

.btn .arrow { font-size: 1.05em; line-height: 1; }

/* ------------------------------------------------------------
   Footer
   ------------------------------------------------------------ */

.site-footer {
  margin-top: auto;
  border-top: 1px solid rgba(220, 227, 238, .9);
}

.site-footer .shell {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 14px 0 18px;
  color: #8792a4;
  font-size: .78rem;
}

.site-footer strong {
  color: #64748b;
  font-weight: 800;
  letter-spacing: .04em;
}

/* ------------------------------------------------------------
   Utility
   ------------------------------------------------------------ */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: 14px;
  top: -60px;
  z-index: 10;
  padding: 12px 18px;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  font-size: .88rem;
  font-weight: 800;
  text-decoration: none;
  transition: top .15s ease;
}
.skip-link:focus { top: 12px; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}