/* AI Coding Standard front page. Tokens, font stack and header follow web/keyword-course/assets/site.css
   so moving from / to /cnlab/ reads as one site. The course has no dark theme, so neither does this page. */

:root{
  --paper:#faf9f6;--surface:#fff;--ink:#242a31;--muted:#5b6368;--line:#ccd2d1;--line-soft:#e4e8e6;
  --green:#1e5d50;--green-deep:#123b32;--green-soft:#e3efe8;--pale:#edf4ef;--focus:#237d63
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:72px;color-scheme:light}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.75 -apple-system,BlinkMacSystemFont,"Apple SD Gothic Neo","Noto Sans KR",sans-serif;word-break:keep-all;-webkit-font-smoothing:antialiased}
a{color:var(--green);text-underline-offset:3px}
a:hover{color:var(--green-deep)}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.skip{position:absolute;left:16px;top:-100px;background:var(--surface);padding:12px;z-index:10}
.skip:focus{top:8px}

/* header — same box as the course topbar */
.topbar{position:sticky;top:0;z-index:5;background:var(--paper);border-bottom:1px solid var(--line)}
.topbar-inner{max-width:1280px;margin:auto;padding:0 32px;height:56px;display:flex;align-items:center;gap:24px}
.brand{display:inline-flex;align-items:center;min-height:44px;margin:0 -8px;padding:6px 8px;border-radius:6px;font-size:16px;font-weight:700;color:var(--ink);text-decoration:none;letter-spacing:-.2px;white-space:nowrap}
.brand:hover{color:var(--ink)}
.author{margin-left:auto;font-size:13px;font-weight:600;white-space:nowrap}
.wm-ai{color:var(--green)}

/* page column — same width and rhythm as the course home */
.portal{max-width:760px;margin:0 auto;padding:0 32px 48px;font-size:17px;line-height:1.8}
.hero{padding:64px 0 56px}
.hero h1{margin:0 0 20px;font-size:clamp(28px,3.2vw,34px);line-height:1.3;letter-spacing:-.5px;font-weight:700;text-wrap:balance}
.eyebrow{margin:0 0 12px;font-size:13px;font-weight:700;letter-spacing:.04em;color:var(--green)}
.lead{max-width:34em;margin:0 0 14px;font-size:18px;line-height:1.75;color:var(--muted);text-wrap:pretty}
.lead:last-child{margin-bottom:0}

/* lecture list */
.lectures h2{margin:0 0 16px;font-size:26px;line-height:1.35;letter-spacing:-.3px}
.lecture-list{list-style:none;margin:0;padding:0;display:grid;gap:16px}
.lecture{position:relative;padding:28px 32px 24px;background:var(--surface);border:1px solid var(--line);border-radius:10px;transition:border-color .15s,box-shadow .15s}
.lecture:hover{border-color:var(--green);box-shadow:0 2px 10px rgba(36,42,49,.08)}
.lecture:focus-within{border-color:var(--green)}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;margin:-1px;padding:0;border:0}
.lecture-top{display:flex;align-items:center;gap:12px;margin:0 0 10px;min-height:28px}
.lecture-mark{display:block;width:auto;height:22px;transform:rotate(-3deg);transform-origin:0 100%;user-select:none;pointer-events:none}
.lecture-version{margin-left:auto;font-size:13px;line-height:1.5;padding:1px 8px;border:1px solid var(--line);border-radius:999px;font-variant-numeric:tabular-nums;color:var(--muted);background:var(--surface);white-space:nowrap}
.lecture-title{margin:0 0 8px;font-size:22px;line-height:1.4;letter-spacing:-.3px;font-weight:700}
.lecture-title a{color:var(--ink);text-decoration:none}
.lecture-title a::after{content:"";position:absolute;inset:0;border-radius:10px}
.lecture-title a:focus-visible{outline:none}
.lecture-title a:focus-visible::after{outline:2px solid var(--focus);outline-offset:2px}
.lecture:hover .lecture-title a{color:var(--green)}
.lecture-desc{margin:0 0 14px;max-width:36em;font-size:16px;line-height:1.7;color:var(--muted);text-wrap:pretty}
.lecture-info,.lecture-stages{margin:0;font-size:14px;line-height:1.7;color:var(--ink);text-wrap:pretty}
.lecture-info{margin-bottom:4px}
.lecture-stages{margin-bottom:20px}
.info-label{font-weight:600}
.sep{color:var(--muted);padding:0 2px}
.lecture-foot{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin:0;padding-top:16px;border-top:1px solid var(--line-soft)}
.lecture-date{font-size:13px;color:var(--muted);font-variant-numeric:tabular-nums}
.lecture-go{font-size:15px;font-weight:600;color:var(--green);white-space:nowrap}

/* buttons (404) — same as the course .btn */
.actions{display:flex;flex-wrap:wrap;gap:10px;margin:28px 0 0}
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:8px 18px;font-size:15px;font-weight:600;line-height:1.3;border:1px solid var(--line);border-radius:6px;background:var(--surface);color:var(--green);text-decoration:none;text-align:center}
.btn:hover{border-color:var(--green);background:var(--pale);color:var(--green)}
.btn.primary{background:var(--green);color:#fff;border-color:var(--green)}
.btn.primary:hover{background:var(--green-deep);border-color:var(--green-deep);color:#fff}

/* footer — same line as the course footer */
.footer{border-top:1px solid var(--line-soft);margin-top:72px;padding:20px 0 0}
.footer-meta{font-size:12px;color:var(--muted);margin:0;font-variant-numeric:tabular-nums}

@media(max-width:1000px){
  .topbar-inner{padding:0 24px;gap:16px}
  .portal{padding:0 24px 48px}
}
@media(max-width:700px){
  .topbar-inner{padding:0 16px;gap:12px}
  .brand{font-size:15px}
  .author{font-size:12px}
  .portal{padding:0 16px 40px}
  .hero{padding:40px 0 40px}
  .hero h1{font-size:28px}
  .lead{font-size:17px;line-height:1.7}
  .lectures h2{font-size:22px}
  .lecture{padding:20px 18px 18px}
  .lecture-title{font-size:19px}
  .lecture-desc{font-size:15px;margin-bottom:12px}
  .lecture-info,.lecture-stages{font-size:13.5px}
  .lecture-info .item{display:block}
  .lecture-info .sep{display:none}
  .actions .btn{flex:1 1 100%}
  .footer{margin-top:56px}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}