/* 디자인 시스템: 블루 Primary + 슬레이트 뉴트럴, Inter, 4px 그리드, 2~4px 라운드, 1px 테두리 */

/* ---------- 토큰 ---------- */
:root {
  /* 브랜드 */
  --primary: #2560ff;
  --primary-dark: #003db5;
  --primary-hover: #0049d9;
  --link: #2560ff;
  --link-hover: #3860be;
  --focus-tint: #c0e0fa;
  --accent: #68b631;            /* 채움 전용. 글자색으로 쓰지 않는다 */
  --on-accent: #2c333f;

  /* 뉴트럴 */
  --white: #ffffff;
  --bg: #f9fafb;
  --surface: #ffffff;
  --code-bg: #e7eaef;
  --border: #c8cfda;
  --border-strong: #a9b4c6;
  --muted: #8b99b2;             /* 장식용 */
  --text-3: #566581;            /* 보조 텍스트 */
  --text-2: #434c5f;            /* 설명 텍스트 */
  --text: #2c333f;
  --black: #000000;
  --divider: #2c333f;

  /* 서버 랙 (텍스트 슬레이트 계열을 그대로 씀) */
  --rack: #2c333f;
  --rack-2: #434c5f;
  --rack-3: #566581;
  --rack-hole: #1b2029;

  /* 타이포 */
  --font-sans: Inter, "Pretendard Variable", Pretendard, system-ui, -apple-system, "Apple SD Gothic Neo", sans-serif;
  --font-display: Repro, Inter, "Pretendard Variable", Pretendard, system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, monospace;

  /* 형태 */
  --radius-xs: 1px;
  --radius-sm: 2px;
  --radius-md: 4px;
  --shadow-ring: rgb(192, 224, 250) 0 0 1px 1px inset;
  --shadow-ring-rest: rgba(0, 0, 0, 0) 0 0 1px 1px inset;
  --shadow-elevated: rgba(0, 0, 0, 0.14) 0 50px 40px 0;
  --ease: ease;
  /* 라이트 전용. OS가 다크 모드여도 폼 컨트롤까지 밝게 유지한다 */
  color-scheme: only light;
}

/* ---------- 기본 ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.5;
  word-break: keep-all;
}
a { color: var(--link); text-decoration: none; transition: color .25s var(--ease); }
a:hover { color: var(--link-hover); }
code, kbd { font-family: var(--font-mono); font-size: 0.875em; }
:not(pre) > code { background: var(--code-bg); padding: 1px 6px; border-radius: var(--radius-sm); }
pre {
  background: var(--code-bg); border-radius: var(--radius-md);
  padding: 16px; overflow-x: auto; font-size: 13px; line-height: 1.5;
}
:focus-visible { outline: none; box-shadow: 0 0 0 3px var(--focus-tint); }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }
.wrap-wide { max-width: 1120px; margin: 0 auto; padding: 0 32px; }
.eyebrow { font-size: 12px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-3); }

/* ---------- 헤더 ---------- */
.site-header { position: sticky; top: 0; z-index: 10; background: var(--surface); border-bottom: 1px solid var(--divider); }
.site-header .inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 64px; }
.brand { color: var(--text); font-weight: 600; font-size: 16px; display: flex; align-items: center; gap: 10px; }
.brand:hover { color: var(--text); }
.brand { min-width: 0; }
.brand .mark { flex: none; display: block; width: 26px; height: 26px; color: var(--text); }
.brand-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* 헤더 오른쪽: Profile 링크와 깃허브 */
.header-nav { flex: none; display: flex; align-items: center; gap: 4px; }
.nav-link { display: inline-flex; align-items: center; min-height: 44px; padding: 0 12px; border-radius: var(--radius-md); font-size: 14px; font-weight: 600; color: var(--text); }
.nav-link:hover { background: var(--code-bg); color: var(--black); }

/* 깃허브 버튼 */
.gh-link {
  flex: none; display: grid; place-items: center; width: 44px; height: 44px;
  border-radius: var(--radius-md); color: var(--text);
  transition: background-color .2s var(--ease), color .2s var(--ease);
}
.gh-link:hover { background: var(--code-bg); color: var(--black); }
.gh-mark { display: block; width: 24px; height: 24px; }
.brand span.sub { color: var(--text-3); font-weight: 500; font-size: 14px; }

/* ---------- 버튼 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 8px 12px;
  font-family: inherit; font-size: 14px; font-weight: 600; line-height: 1.2;
  border-radius: var(--radius-md); cursor: pointer;
  background: var(--surface); color: var(--black);
  border: 1px solid var(--border-strong); box-shadow: var(--shadow-ring-rest);
  transition: background-color .2s var(--ease), border-color .2s var(--ease), color .1s var(--ease);
}
.btn:hover { background: var(--bg); border-color: var(--muted); color: var(--black); }
.btn:focus-visible { border-color: var(--primary); box-shadow: 0 0 0 3px var(--focus-tint); }
.btn.primary { background: var(--primary); color: #fff; border-color: var(--primary-dark); box-shadow: var(--shadow-ring); }
.btn.primary:hover { background: var(--primary-hover); color: #fff; }
.btn.primary:focus-visible { box-shadow: var(--shadow-ring), 0 0 0 3px var(--focus-tint); }
.btn:disabled { cursor: not-allowed; background: var(--code-bg); color: var(--text-3); border-color: var(--border); box-shadow: none; }

/* ---------- 배지 (2px 라운드) ---------- */
.badge { display: inline-block; font-size: 12px; font-weight: 600; padding: 4px 8px; border-radius: var(--radius-sm); white-space: nowrap; line-height: 1.2; }
.badge.todo { background: var(--code-bg); color: var(--text-3); }
.badge.draft { padding: 3px 7px; border: 1px solid var(--border-strong); color: var(--text); }
.badge.understood { background: var(--primary); color: #fff; }
.badge.interview { background: var(--accent); color: var(--on-accent); }

/* ---------- 카드 ---------- */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 24px; }

/* ---------- 홈: 히어로 ---------- */
.hero { display: grid; grid-template-columns: minmax(0, 1fr) 380px; gap: 40px; align-items: center; padding: 56px 0 40px; }
.hero .eyebrow { margin-bottom: 16px; }
.hero h1 { font-family: var(--font-display); font-size: clamp(36px, 5vw, 56px); line-height: 1.05; font-weight: 600; letter-spacing: -0.03em; margin: 0 0 20px; }
.hero h1 em { font-style: normal; color: var(--link); white-space: nowrap; }
.h1-sub { display: block; margin-top: 10px; font-size: .5em; font-weight: 500; letter-spacing: -0.01em; color: var(--text-2); }

/* ---------- 운영자 출입증 ---------- */
.op-badge {
  position: relative; display: flex; flex-direction: column; color: var(--text);
  background: var(--surface); border: 1px solid var(--border); border-radius: 10px; overflow: hidden;
  box-shadow: rgba(44, 51, 63, .08) 0 12px 24px -8px;
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .2s var(--ease);
}
a.op-badge:hover { color: var(--text); transform: translateY(-4px) rotate(-.6deg); border-color: var(--border-strong); box-shadow: rgba(44, 51, 63, .14) 0 18px 32px -10px; }
.op-strap { height: 26px; background: var(--rack); display: grid; place-items: center; }
.op-hole { width: 44px; height: 8px; border-radius: 99px; background: var(--bg); }
.op-head { display: flex; align-items: center; gap: 8px; padding: 12px 20px 0; font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-3); }
.op-led { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 6px var(--accent); }
.op-body { display: flex; gap: 16px; align-items: center; padding: 16px 20px 18px; }
.op-avatar { flex: none; width: 64px; height: 64px; border-radius: 8px; border: 1px solid var(--border); background: var(--code-bg); object-fit: cover; }
.op-id { min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.op-name { font-size: 22px; font-weight: 700; line-height: 1.2; }
.op-name span { margin-left: 8px; font-size: 13px; font-weight: 500; color: var(--text-3); }
.op-school { font-size: 15px; color: var(--text-2); }
.op-school strong { color: var(--primary-dark); font-weight: 700; }
.op-en { font-family: var(--font-mono); font-size: 11px; color: var(--text-3); }
.op-foot { display: flex; justify-content: space-between; gap: 12px; padding: 10px 20px; border-top: 1px dashed var(--border); font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--text-3); }
.op-foot span:last-child { color: var(--link); }
.op-badge.big { max-width: 520px; margin: 12px 0 8px; }
.op-badge.big .op-avatar { width: 88px; height: 88px; }
.op-badge.big .op-name { font-size: 28px; }

/* ---------- 프로필 화면 ---------- */
.edu { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 20px 24px; }
.edu-school { font-size: 22px; font-weight: 700; }
.edu-major { font-size: 17px; font-weight: 600; color: var(--primary-dark); margin-top: 2px; }
.edu-major span { color: var(--text); margin-left: 6px; }
.edu-en { font-family: var(--font-mono); font-size: 12px; color: var(--text-3); margin-top: 6px; }
.timeline { list-style: none; padding: 0; margin: 12px 0 0; border-left: 2px solid var(--border); }
.timeline li { position: relative; display: grid; gap: 2px; padding: 0 0 20px 20px; margin: 0; }
.timeline li + li { margin-top: 0; }
.timeline li::before { content: ""; position: absolute; left: -7px; top: 6px; width: 12px; height: 12px; border-radius: 50%; background: var(--surface); border: 2px solid var(--primary); }
.tl-kind { font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--link); }
.timeline strong { font-size: 17px; }
.tl-org { font-size: 15px; color: var(--text-2); }
.tl-period { font-family: var(--font-mono); font-size: 12px; color: var(--text-3); }
.profile h3 { font-size: 14px; font-weight: 600; color: var(--text-2); margin: 16px 0 8px; }
.contact-list { list-style: none; padding: 0; margin: 12px 0 0; display: grid; gap: 8px; }
.contact-list li { display: grid; grid-template-columns: 96px minmax(0, 1fr); align-items: center; gap: 12px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 12px 16px; margin: 0; }
.contact-list span { font-size: 13px; font-weight: 600; color: var(--text-3); }
.contact-list a { font-family: var(--font-mono); font-size: 14px; overflow-wrap: anywhere; }
.hero p { font-size: 18px; color: var(--text-2); margin: 0; max-width: 560px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
/* ---------- 화면 전환 ---------- */
/* 같은 랙(view-transition-name)은 제자리에서 다음 위치로 날아가고, 나머지 화면은 흐려졌다가 아래에서 떠오른다 */
@view-transition { navigation: auto; }   /* 주제 페이지로 오갈 때도 부드럽게 (지원 브라우저) */
.site-header { view-transition-name: site-header; }
::view-transition-group(*) { animation-duration: .55s; animation-timing-function: cubic-bezier(.2, .8, .2, 1); }
::view-transition-old(root) { animation: vt-out .22s ease both; }
::view-transition-new(root) { animation: vt-in .5s cubic-bezier(.2, .8, .2, 1) .08s both; }
@keyframes vt-out { to { opacity: 0; transform: scale(.985); } }
@keyframes vt-in { from { opacity: 0; transform: translateY(14px); } }
.app-enter { animation: vt-in .45s cubic-bezier(.2, .8, .2, 1) both; }   /* 전환 기능이 없는 브라우저용 */
@media (prefers-reduced-motion: reduce) {
  ::view-transition-group(*), ::view-transition-old(*), ::view-transition-new(*) { animation: none !important; }
}

/* ---------- 랙 화면 ---------- */
.rack-nav { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; padding: 24px 0 8px; }
.back-link { display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 0 12px 0 8px; margin-left: -8px; border-radius: var(--radius-md); font-size: 14px; font-weight: 600; color: var(--text-2); }
.back-link:hover { background: var(--code-bg); color: var(--text); }
.rack-switch { display: flex; gap: 8px; }
.rack-switch .btn { font-family: var(--font-mono); font-size: 13px; }
.rack-view { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 48px; align-items: start; padding: 16px 0 80px; }
.rack-view-art { position: sticky; top: 88px; }
.rack-view-body h1 { font-family: var(--font-display); font-size: clamp(32px, 4vw, 44px); line-height: 1.1; font-weight: 500; letter-spacing: -0.02em; margin: 8px 0 8px; width: fit-content; }
.rack-desc { margin: 0 0 24px; color: var(--text-2); font-size: 16px; }
.rack-view .server-grid { grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); margin-top: 0; }

/* ---------- 데이터센터: 랙 여러 대 ---------- */
.room { display: flex; flex-wrap: wrap; justify-content: center; align-items: flex-end; gap: 24px 20px; padding: 8px 0 40px; }
.rack-card { width: 220px; display: flex; flex-direction: column; align-items: center; gap: 8px; }
.rack-art { width: 100%; display: block; }
.rack-art.clickable { cursor: pointer; }
.rack-plate-link { outline: none; }
.rack-plate-link:hover .rack-plate, .rack-plate-link:focus-visible .rack-plate { fill: var(--primary); }
.rack-label { display: flex; flex-direction: column; align-items: center; gap: 0; text-align: center; color: var(--text); padding: 4px 8px; border-radius: var(--radius-md); }
.rack-label:hover { color: var(--text); background: var(--surface); box-shadow: inset 0 0 0 1px var(--border); }
.rack-id { font-family: var(--font-mono); font-size: 11px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--link); }
.rack-name { font-size: 15px; font-weight: 600; }
.rack-meta { font-size: 12px; color: var(--text-3); }

/* 랙 그림 (SVG) */
.rack-frame { fill: var(--rack); }
.rack-plate { fill: var(--rack-3); }
.rack-plate-text { font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .08em; fill: #fff; }
.rack-rail { fill: var(--rack-3); }
.rack-hole { fill: var(--rack-hole); }
.rack-foot { fill: var(--rack); }
.blank { fill: var(--rack-2); opacity: .55; }
.blank-line { stroke: var(--rack); stroke-width: 2; stroke-linecap: round; }
.unit { cursor: pointer; transition: transform .3s var(--ease); outline: none; }
.unit:hover, .unit:focus-visible { transform: translateX(-8px); }
.unit-body { fill: var(--rack-2); stroke: var(--rack-3); stroke-width: 1; }
.unit:hover .unit-body, .unit:focus-visible .unit-body { stroke: var(--focus-tint); }
.unit.current .unit-body { stroke: var(--primary); stroke-width: 2; }
.unit-no { font-family: var(--font-mono); font-size: 10px; font-weight: 700; letter-spacing: .04em; fill: var(--border-strong); }
.unit-count { font-family: var(--font-mono); font-size: 10px; font-weight: 700; fill: var(--focus-tint); }
.unit-title { font-family: var(--font-sans); font-size: 15px; font-weight: 600; fill: #fff; }
.vent { fill: var(--rack); }
.power { fill: var(--rack-3); }
.power.on { fill: var(--accent); filter: drop-shadow(0 0 3px var(--accent)); }
.activity { fill: var(--focus-tint); opacity: .25; animation: blink 2.2s steps(1) infinite; }
.led { fill: var(--rack); stroke: var(--rack-3); stroke-width: 1; }
.led.draft { fill: var(--focus-tint); stroke: none; animation: breathe 2.4s var(--ease) infinite; }
.led.understood { fill: var(--primary); stroke: var(--focus-tint); filter: drop-shadow(0 0 3px var(--primary)); }
.led.interview { fill: var(--accent); stroke: none; filter: drop-shadow(0 0 4px var(--accent)); }
@keyframes blink { 0%, 100% { opacity: .25; } 8%, 14% { opacity: 1; } 11% { opacity: .25; } }
@keyframes breathe { 0%, 100% { opacity: .45; } 50% { opacity: 1; } }
@media (prefers-reduced-motion: reduce) {
  .activity, .led.draft { animation: none; }
  .unit { transition: none; }
}

/* 램프 점 (목록, 범례) */
.led-dot { display: inline-block; flex: none; width: 10px; height: 10px; border-radius: 50%; background: var(--code-bg); box-shadow: inset 0 0 0 1px var(--border-strong); }
.led-dot.draft { background: var(--focus-tint); box-shadow: inset 0 0 0 1px var(--primary); }
.led-dot.understood { background: var(--primary); box-shadow: 0 0 0 2px var(--focus-tint); }
.led-dot.interview { background: var(--accent); box-shadow: 0 0 0 2px #d9eecb; }

/* ---------- 홈: 특징 ---------- */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; padding: 0 0 48px; }
.feature { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 24px; display: flex; flex-direction: column; gap: 12px; }
.feature h3 { margin: 0; font-size: 20px; line-height: 1.2; font-weight: 500; letter-spacing: -0.01em; }
.feature p { margin: 0; color: var(--text-2); font-size: 14px; }
.feature .ico { width: 40px; height: 40px; display: grid; place-items: center; border-radius: var(--radius-md); background: var(--code-bg); color: var(--primary); }

/* ---------- 홈: 랙 모니터 ---------- */
.monitor { background: var(--surface); border: 1px solid var(--border); border-top: 3px solid var(--rack); border-radius: var(--radius-md); padding: 24px; margin-bottom: 64px; }
.monitor-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; flex-wrap: wrap; }
.monitor-head .eyebrow { margin-bottom: 4px; }
.monitor-head strong { font-size: 24px; font-weight: 600; }
.monitor-stats { display: flex; gap: 8px; flex-wrap: wrap; }
.monitor-stats span { font-family: var(--font-mono); font-size: 12px; padding: 4px 8px; border-radius: var(--radius-sm); background: var(--code-bg); color: var(--text-2); }
.monitor-stats b { color: var(--text); }
.progress-bar { display: flex; height: 12px; border-radius: var(--radius-sm); overflow: hidden; background: var(--code-bg); margin: 16px 0 12px; }
.progress-bar span { display: block; height: 100%; transition: width 1s var(--ease); }
.legend { display: flex; gap: 16px; flex-wrap: wrap; font-size: 13px; color: var(--text-2); }
.legend span { display: inline-flex; align-items: center; gap: 8px; }

/* ---------- 홈: 챕터 목록 ---------- */
.toc-head { display: flex; flex-direction: column; gap: 4px; margin-bottom: 24px; }
.toc-title { font-family: var(--font-display); font-size: 32px; line-height: 1.15; font-weight: 500; letter-spacing: -0.01em; margin: 0; }
.toc-sub { color: var(--text-2); margin: 0; font-size: 14px; }
.chapter { display: grid; grid-template-columns: 72px 1fr; gap: 8px 24px; padding: 32px 0; border-top: 1px solid var(--border); }
.chapter-no { font-family: var(--font-mono); font-size: 24px; font-weight: 600; color: var(--primary); line-height: 1.2; }
.chapter h3 { margin: 0; font-size: 20px; line-height: 1.3; font-weight: 600; }

/* 장비 목록: 랙 단위 묶음 */
.rack-section { margin-bottom: 28px; scroll-margin-top: 80px; }
.rack-section-head {
  display: grid; grid-template-columns: auto 1fr auto; gap: 12px; align-items: center;
  padding: 0 0 10px; border-bottom: 1px solid var(--border);
}
.rack-section-head h2 { margin: 0; font-size: 18px; line-height: 1.2; font-weight: 600; color: var(--text); }
.rack-section-head p { margin: 2px 0 0; font-size: 13px; color: var(--text-2); }
.rack-chip { font-family: var(--font-mono); font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; background: var(--focus-tint); color: var(--primary-dark); border-radius: var(--radius-sm); padding: 6px 10px; white-space: nowrap; }
.rack-section-meta { font-family: var(--font-mono); font-size: 12px; background: var(--code-bg); color: var(--text-2); border-radius: var(--radius-sm); padding: 4px 8px; white-space: nowrap; }

/* 서버 카드: 랙 안의 과목을 가로로 작게 */
.server-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 10px; margin-top: 10px; }
.server-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); overflow: hidden; display: flex; flex-direction: column; color: var(--text); }
.server-card { transition: border-color .2s var(--ease); }
.server-card:hover, .server-card:focus-visible { border-color: var(--primary); color: var(--text); }
.server-card-head { display: flex; flex-direction: column; gap: 2px; padding: 10px 12px 8px; border-bottom: 1px solid var(--code-bg); color: var(--text); }
.server-card-title { display: flex; align-items: center; gap: 6px; }
.server-card-head h3 { margin: 0; font-size: 15px; font-weight: 600; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.unit-tag { font-family: var(--font-mono); font-size: 10px; font-weight: 700; letter-spacing: .06em; color: var(--link); }
.server-lamps { font-family: var(--font-mono); font-size: 10px; background: var(--code-bg); color: var(--text-2); border-radius: var(--radius-sm); padding: 1px 5px; }
.server-card-desc { margin: 0; padding: 10px 12px 12px; font-size: 13px; line-height: 1.5; color: var(--text-2); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.chapter .desc { margin: 4px 0 16px; color: var(--text-2); font-size: 14px; }
.topic-list { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 4px 24px; }
.topic-list a, .topic-list .disabled {
  display: flex; align-items: center; gap: 12px; min-height: 44px; padding: 8px 12px; margin: 0 -12px;
  border-radius: var(--radius-md); color: var(--text);
}
.topic-list a:hover { background: var(--surface); box-shadow: inset 0 0 0 1px var(--border); color: var(--text); }
.topic-list a:hover .name { color: var(--link-hover); }
.topic-list .name { font-weight: 600; font-size: 16px; white-space: nowrap; transition: color .25s var(--ease); }
.topic-list .hook { color: var(--text-3); font-size: 13px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1; min-width: 0; }
.topic-list .disabled .name { color: var(--text-3); font-weight: 500; }
.topic-list .badge { margin-left: auto; }
.topic-list.server-topics { grid-template-columns: minmax(0, 1fr); }

/* ---------- 주제 페이지 ---------- */
.crumb { font-size: 14px; font-weight: 600; color: var(--text-3); margin: 48px 0 16px; display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.crumb .sep { color: var(--muted); }
.article h1 { font-family: var(--font-display); font-size: clamp(32px, 5vw, 48px); line-height: 1.1; font-weight: 500; letter-spacing: -0.02em; margin: 0 0 16px; }
.article .lead { font-size: 18px; color: var(--text-2); margin: 0 0 40px; }
.article h2 { font-size: 24px; font-weight: 600; line-height: 1.3; margin: 64px 0 12px; display: flex; align-items: center; gap: 12px; }
.article h2 .step { font-family: var(--font-mono); font-size: 12px; font-weight: 600; color: #fff; background: var(--primary); border-radius: var(--radius-sm); padding: 4px 8px; line-height: 1.2; }
.article h3 { font-size: 18px; font-weight: 600; margin: 32px 0 8px; }
.article p, .article li { font-size: 17px; line-height: 1.75; }
.article li + li { margin-top: 4px; }
.note { background: var(--code-bg); border-radius: var(--radius-md); padding: 16px; margin: 24px 0; font-size: 14px; color: var(--text-2); }
.note strong { color: var(--text); }

/* 인터랙티브 영역 */
.lab { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 24px; margin: 24px 0 8px; }
.lab-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; gap: 12px; flex-wrap: wrap; }
.lab-controls { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-bottom: 12px; }
.lab label.field { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 600; }
.lab input[type="text"], .lab select {
  font-family: inherit; font-size: 14px; min-height: 44px; padding: 0 12px;
  border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); color: var(--text);
}
.lab input[type="text"] { width: 180px; }
.lab input[type="text"]:focus, .lab select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--focus-tint); }
.lab-log { font-family: var(--font-mono); font-size: 13px; background: var(--code-bg); border-radius: var(--radius-md); padding: 16px; min-height: 52px; color: var(--text); margin-top: 16px; white-space: pre-wrap; }
.lab-caption { font-size: 13px; color: var(--text-3); text-align: center; margin: 0 0 24px; }

/* 면접 질문 */
.qa { border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); margin: 8px 0; }
.qa summary { cursor: pointer; min-height: 44px; padding: 12px 16px; font-weight: 600; list-style: none; display: flex; gap: 12px; align-items: baseline; }
.qa summary::-webkit-details-marker { display: none; }
.qa summary::before { content: "Q"; font-family: var(--font-mono); font-size: 13px; color: var(--link); }
.qa summary::after { content: "+"; margin-left: auto; color: var(--text-3); font-family: var(--font-mono); }
.qa[open] summary::after { content: "−"; }
.qa[open] summary { border-bottom: 1px solid var(--border); }
.qa .answer { padding: 16px; color: var(--text-2); font-size: 15px; }

/* 이전/다음 */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 64px 0 96px; }
.pager a { border: 1px solid var(--border); border-radius: var(--radius-md); padding: 16px 24px; background: var(--surface); color: var(--text); font-weight: 600; transition: border-color .2s var(--ease); }
.pager a:hover { border-color: var(--primary); color: var(--text); }
.pager small { display: block; color: var(--text-3); font-size: 12px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 4px; }
.pager .next { text-align: right; grid-column: 2; }

.site-footer { border-top: 1px solid var(--border); color: var(--text-3); font-size: 13px; padding: 32px 0 48px; }

/* ---------- 홈: 구역 제목 (Lab / Production) ---------- */
.zone-head { display: flex; align-items: baseline; gap: 8px 12px; flex-wrap: wrap; padding-bottom: 12px; margin: 8px 0 24px; border-bottom: 1px solid var(--border); }
.zone-head h2 { margin: 0; font-size: 22px; font-weight: 600; }
.zone-head p { margin: 0; font-size: 14px; color: var(--text-2); }
.zone-tag { align-self: center; font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; background: var(--focus-tint); color: var(--primary-dark); border-radius: var(--radius-sm); padding: 4px 8px; }
.zone-tag.prod { background: var(--accent); color: var(--on-accent); }

/* ---------- Production 랙 (가로) ---------- */
.prod-rack {
  position: relative; background: var(--rack); border-radius: 6px; padding: 48px 40px 20px; margin-bottom: 80px;
}
.prod-rack::before, .prod-rack::after {
  content: ""; position: absolute; top: 40px; bottom: 12px; width: 10px;
  background-color: var(--rack-3);
  background-image: repeating-linear-gradient(to bottom, transparent 0 9px, var(--rack-hole) 9px 12px);
  background-size: 3px 100%; background-position: center; background-repeat: no-repeat;
}
.prod-rack::before { left: 16px; }
.prod-rack::after { right: 16px; }
.prod-plate {
  position: absolute; top: 12px; left: 50%; transform: translateX(-50%);
  font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .08em; white-space: nowrap;
  color: #fff; background: var(--rack-3); border-radius: var(--radius-sm); padding: 4px 12px;
}
.prod-slots { display: flex; flex-direction: column; gap: 8px; }
.prod-server {
  display: grid; grid-template-columns: auto minmax(140px, auto) minmax(0, 1fr) auto auto; align-items: center; gap: 20px;
  min-height: 68px; padding: 10px 20px; border-radius: 3px;
  background: var(--rack-2); border: 1px solid var(--rack-3); color: #fff;
  transition: transform .3s var(--ease), border-color .2s var(--ease);
}
.prod-server:hover, .prod-server:focus-visible { color: #fff; transform: translateX(-8px); border-color: var(--focus-tint); }
.prod-id { display: flex; flex-direction: column; gap: 2px; }
.prod-host { font-family: var(--font-mono); font-size: 11px; font-weight: 700; letter-spacing: .04em; color: var(--border-strong); }
.prod-name { font-size: 18px; font-weight: 600; line-height: 1.2; }
.prod-summary { font-size: 14px; color: var(--border); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.prod-stack { display: flex; gap: 4px; flex-wrap: wrap; justify-content: flex-end; }
.prod-stack span { font-family: var(--font-mono); font-size: 11px; background: var(--rack); color: var(--border); border-radius: var(--radius-sm); padding: 2px 6px; }
.prod-status { font-family: var(--font-mono); font-size: 11px; font-weight: 700; color: var(--border-strong); white-space: nowrap; }
.sample-tag { font-family: var(--font-sans); font-size: 11px; font-weight: 600; letter-spacing: 0; background: var(--accent); color: var(--on-accent); border-radius: var(--radius-sm); padding: 1px 6px; margin-left: 4px; }
.prod-led { flex: none; width: 10px; height: 10px; border-radius: 50%; background: var(--rack-3); }
.prod-led.live { background: var(--accent); box-shadow: 0 0 6px var(--accent); }
.prod-led.dev { background: var(--focus-tint); box-shadow: 0 0 6px var(--focus-tint); animation: breathe 2.4s var(--ease) infinite; }
.prod-blank {
  height: 68px; border-radius: 3px; background-color: #3a4252;
  background-image: repeating-linear-gradient(to bottom, transparent 0 14px, var(--rack) 14px 16px);
  background-size: calc(100% - 64px) 100%; background-position: center; background-repeat: no-repeat;
}

/* ---------- 프로젝트 화면 ---------- */
.project { max-width: 880px; padding-bottom: 80px; }
.prod-face {
  display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: 20px; align-items: center;
  background: var(--rack-2); border: 1px solid var(--rack-3); border-radius: var(--radius-md); padding: 24px 28px; margin: 16px 0 24px; color: #fff;
}
.project .prod-face h1 { color: #fff; margin: 4px 0; font-size: clamp(28px, 4vw, 40px); }
.project .prod-face p { margin: 0; color: var(--border); font-size: 16px; line-height: 1.5; }
.prod-links { display: flex; gap: 8px; flex-wrap: wrap; }
.prod-links .btn[aria-disabled] { cursor: not-allowed; background: var(--rack); color: var(--border-strong); border-color: var(--rack-3); }
.project-meta { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 0; }
.project-meta div { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 12px 16px; }
.project-meta dt { font-size: 12px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--text-3); }
.project-meta dd { margin: 2px 0 0; font-size: 15px; font-weight: 600; }
.stack-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.stack-chips span { font-family: var(--font-mono); font-size: 13px; background: var(--focus-tint); color: var(--primary-dark); border-radius: var(--radius-sm); padding: 4px 10px; }
.arch-flow { list-style: none; padding: 0; margin: 12px 0; display: flex; flex-wrap: wrap; align-items: center; gap: 12px 30px; }
.arch-flow li { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 8px 14px; font-size: 14px; font-weight: 600; }
.arch-flow li + li { margin-top: 0; }
.arch-flow li:not(:last-child)::after { content: "→"; position: absolute; right: -22px; top: 50%; transform: translateY(-50%); color: var(--muted); font-weight: 400; }
.trouble { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 20px 24px; margin: 12px 0; }
.trouble h3 { margin: 0 0 12px; }
.trouble dl { display: grid; grid-template-columns: 48px minmax(0, 1fr); gap: 8px 16px; margin: 0; }
.trouble dt { font-family: var(--font-mono); font-size: 12px; font-weight: 700; color: var(--link); padding-top: 3px; }
.trouble dd { margin: 0; font-size: 15px; line-height: 1.6; }
.project .project-intro { margin: 0 0 24px; font-size: 17px; line-height: 1.75; color: var(--text-2); }


/* ---------- 반응형 (1024 / 767 / 425) ---------- */
@media (max-width: 1024px) {
  .hero { grid-template-columns: minmax(0, 1fr) 330px; gap: 28px; }
  .features { grid-template-columns: 1fr 1fr; }
  .rack-card { width: 200px; }
  .server-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 767px) {
  .wrap-wide { padding: 0 16px; }
  .hero { grid-template-columns: 1fr; gap: 24px; padding-top: 32px; }
  .op-body { padding: 14px 16px 16px; }
  .op-head, .op-foot { padding-left: 16px; padding-right: 16px; }
  .brand-name { max-width: 46vw; }
  .contact-list li { grid-template-columns: 1fr; gap: 2px; }
  .room { gap: 20px 16px; }
  .rack-card { width: 160px; }
  .rack-view { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .rack-view-art { position: static; width: 180px; }
  .rack-view .server-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .server-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .rack-section-head { grid-template-columns: 1fr; gap: 8px; }
  .rack-chip, .rack-section-meta { justify-self: start; }
  .brand-name { font-size: 14px; }
  .features { grid-template-columns: 1fr; }
  .chapter { grid-template-columns: 1fr; }
  .chapter-no { font-size: 16px; }
  .topic-list { grid-template-columns: 1fr; }
  .topic-list a, .topic-list .disabled { margin: 0; padding: 8px 4px; }
  .server-topics a, .server-topics .disabled { flex-wrap: wrap; }
  .server-topics .name { flex: 1 1 0; min-width: 0; white-space: normal; }
  .server-topics .hook { order: 3; flex: 0 0 100%; padding-left: 22px; white-space: normal; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { grid-column: 1; }
  .brand span.sub { display: none; }
  .prod-rack { padding: 44px 32px 16px; }
  .prod-rack::before { left: 11px; }
  .prod-rack::after { right: 11px; }
  .prod-server { grid-template-columns: auto minmax(0, 1fr) auto; gap: 6px 12px; padding: 12px 14px; }
  .prod-summary { grid-column: 2 / -1; white-space: normal; }
  .prod-stack { grid-column: 2 / -1; justify-content: flex-start; }
  .prod-status { grid-row: 1; grid-column: 3; }
  .prod-face { grid-template-columns: auto minmax(0, 1fr); padding: 20px; }
  .prod-links { grid-column: 1 / -1; }
  .project-meta { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { .prod-led.dev { animation: none; } .prod-server { transition: none; } }