/* ===== Harness Ad Academy — Site Design System ===== */
:root{
  --navy:#1E293B; --navy-2:#0F172A; --coral:#FF6B4A; --teal:#2DD4BF; --teal-d:#0D9488;
  --paper:#F8FAFC; --mist:#E2E8F0; --slate:#64748B; --ink:#1E293B; --white:#fff;
  --line:#E7ECF3; --card:#ffffff; --bg:#F6F8FB; --bg-2:#eef2f7;
  --shadow-sm:0 1px 2px rgba(16,24,40,.06),0 1px 3px rgba(16,24,40,.08);
  --shadow:0 6px 24px rgba(16,24,40,.08); --shadow-lg:0 18px 48px rgba(16,24,40,.14);
  --radius:16px; --radius-sm:10px; --maxw:1180px; --readw:760px;
  --pat:#3B82F6; /* per-page override */
  --font:"Pretendard Variable",Pretendard,-apple-system,"Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --mono:"D2Coding","SF Mono",ui-monospace,"JetBrains Mono",Menlo,monospace;
}
:root[data-theme="dark"]{
  /* keep --navy dark: it is a surface color (table headers), not text */
  --ink:#e6edf6; --slate:#94a3b8; --paper:#0f172a;
  --line:#22304a; --mist:#22304a; --card:#111a2e; --bg:#0b1220; --bg-2:#16223c;
  --th-bg:#243a5e;
}
:root[data-theme="dark"] .article thead th{background:var(--th-bg)}
:root[data-theme="dark"] .article table{border-color:var(--line)}
/* text selection: intentional tint, never a pale/white block */
::selection{background:rgba(255,107,74,.28)}
.codeblock ::selection,.codeblock pre::selection,.codeblock code::selection{background:rgba(45,212,191,.40);color:#fff}
*{box-sizing:border-box}
html{scroll-behavior:smooth; scroll-padding-top:88px}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--ink);
  font-size:17px;line-height:1.72;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
img{max-width:100%}

/* ---------- Header ---------- */
.hdr{position:sticky;top:0;z-index:50;backdrop-filter:saturate(1.4) blur(12px);
  background:color-mix(in srgb,var(--bg) 82%,transparent);border-bottom:1px solid var(--line)}
.hdr-in{max-width:var(--maxw);margin:0 auto;padding:12px 22px;display:flex;align-items:center;gap:22px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;letter-spacing:-.01em}
.brand .logo{width:30px;height:30px;border-radius:9px;background:
  conic-gradient(from 210deg,var(--coral),var(--teal),var(--navy),var(--coral));
  box-shadow:var(--shadow-sm)}
.brand small{display:block;font-weight:600;font-size:11px;color:var(--slate);letter-spacing:.06em}
.nav{margin-left:auto;display:flex;align-items:center;gap:6px}
.nav a{padding:8px 13px;border-radius:9px;font-size:14.5px;font-weight:600;color:var(--slate)}
.nav a:hover{color:var(--ink);background:var(--bg-2)}
.iconbtn{width:38px;height:38px;border-radius:10px;border:1px solid var(--line);background:var(--card);
  cursor:pointer;font-size:16px;display:grid;place-items:center;color:var(--slate)}
.iconbtn:hover{color:var(--ink);border-color:var(--slate)}

/* ---------- Hero ---------- */
.hero{position:relative;overflow:hidden;background:
  radial-gradient(1200px 500px at 85% -10%,color-mix(in srgb,var(--teal) 22%,transparent),transparent 60%),
  radial-gradient(900px 460px at 5% 0%,color-mix(in srgb,var(--coral) 18%,transparent),transparent 55%),
  linear-gradient(180deg,#0b1327,#111c34)}
.hero .wrap{max-width:var(--maxw);margin:0 auto;padding:82px 22px 74px;color:#e8eef8;position:relative}
.hero .eyebrow{color:var(--teal);font-weight:800;letter-spacing:.16em;font-size:13px;margin:0 0 16px}
.hero h1{font-size:clamp(34px,5.4vw,62px);line-height:1.06;margin:0 0 18px;font-weight:850;letter-spacing:-.02em;color:#fff}
.hero h1 .hl{color:var(--coral)}
.hero p{font-size:clamp(16px,2vw,21px);color:#b9c6dc;max-width:640px;margin:0 0 30px}
.hero .cta{display:flex;gap:12px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 22px;border-radius:12px;font-weight:700;font-size:15.5px;
  border:1px solid transparent;cursor:pointer;transition:transform .12s ease,box-shadow .12s ease}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--coral);color:#fff;box-shadow:0 8px 26px rgba(255,107,74,.36)}
.btn-ghost{background:rgba(255,255,255,.08);color:#e8eef8;border-color:rgba(255,255,255,.18)}
.hero .stats{display:flex;gap:30px;margin-top:44px;flex-wrap:wrap}
.hero .stats b{display:block;font-size:30px;color:#fff;font-weight:800;line-height:1.1}
.hero .stats span{font-size:13.5px;color:#95a6c2}

/* ---------- Sections ---------- */
.section{max-width:var(--maxw);margin:0 auto;padding:64px 22px}
.section h2.st{font-size:clamp(24px,3.2vw,34px);font-weight:820;letter-spacing:-.02em;margin:0 0 6px}
.section .sub{color:var(--slate);margin:0 0 34px;font-size:16.5px}

/* ---------- Course cards ---------- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.card{position:relative;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 24px 22px;box-shadow:var(--shadow-sm);transition:transform .16s ease,box-shadow .16s ease;overflow:hidden;display:flex;flex-direction:column}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.card::before{content:"";position:absolute;inset:0 0 auto 0;height:5px;background:var(--pat)}
.card .cid{display:inline-flex;align-items:center;justify-content:center;min-width:42px;height:28px;padding:0 10px;
  border-radius:8px;background:var(--pat);color:#fff;font-weight:800;font-size:14px;margin-bottom:14px;align-self:flex-start}
.card h3{font-size:20.5px;margin:0 0 8px;font-weight:800;letter-spacing:-.01em}
.card p{color:var(--slate);font-size:14.5px;margin:0 0 18px;flex:1}
.card .meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:16px}
.chip{font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px;background:var(--bg-2);color:var(--slate)}
.chip.pat{background:color-mix(in srgb,var(--pat) 16%,transparent);color:var(--pat)}
.card .go{font-weight:700;color:var(--pat);font-size:14.5px;display:inline-flex;align-items:center;gap:6px}
.card:hover .go{gap:10px}

/* ---------- Tracks ---------- */
.tracks{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.track{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px 22px;box-shadow:var(--shadow-sm)}
.track h4{margin:0 0 12px;font-size:16px}
.track .flow{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.track .step{font-weight:800;font-size:13px;background:var(--bg-2);border-radius:8px;padding:5px 10px}
.track .arr{color:var(--slate)}

/* ---------- Course page layout ---------- */
.coursebanner{background:linear-gradient(120deg,var(--navy-2),#16233d);color:#eaf0fa;position:relative;overflow:hidden}
.coursebanner::after{content:"";position:absolute;right:-80px;top:-80px;width:360px;height:360px;border-radius:50%;
  background:radial-gradient(circle,color-mix(in srgb,var(--pat) 55%,transparent),transparent 62%);opacity:.5}
.coursebanner .wrap{max-width:var(--maxw);margin:0 auto;padding:46px 22px 40px;position:relative}
.coursebanner .cid{display:inline-block;background:var(--pat);color:#fff;font-weight:800;padding:5px 12px;border-radius:8px;font-size:14px;margin-bottom:14px}
.coursebanner h1{font-size:clamp(26px,4vw,42px);margin:0 0 12px;font-weight:840;letter-spacing:-.02em;color:#fff}
.coursebanner .metarow{display:flex;gap:9px;flex-wrap:wrap}
.coursebanner .chip{background:rgba(255,255,255,.1);color:#dbe4f2}
.coursebanner .chip.pat{background:var(--pat);color:#fff}

.layout{max-width:var(--maxw);margin:0 auto;padding:0 22px;display:grid;grid-template-columns:264px minmax(0,1fr);gap:40px;align-items:start}
.side{position:sticky;top:80px;align-self:start;max-height:calc(100vh - 96px);overflow-y:auto;padding:26px 0 40px}
.side h5{font-size:11px;letter-spacing:.12em;color:var(--slate);text-transform:uppercase;margin:0 0 10px}
.side .courselist{list-style:none;margin:0 0 26px;padding:0;display:flex;flex-direction:column;gap:2px}
.side .courselist a{display:flex;gap:9px;align-items:center;padding:7px 10px;border-radius:9px;font-size:13.5px;font-weight:600;color:var(--slate)}
.side .courselist a .dot{width:8px;height:8px;border-radius:50%;background:var(--cdot,var(--slate));flex:none}
.side .courselist a:hover{background:var(--bg-2);color:var(--ink)}
.side .courselist a.cur{background:color-mix(in srgb,var(--pat) 12%,transparent);color:var(--pat);font-weight:800}
.toc{list-style:none;margin:0;padding:0;border-left:2px solid var(--line);display:flex;flex-direction:column}
.toc a{padding:5px 0 5px 14px;margin-left:-2px;border-left:2px solid transparent;color:var(--slate);font-size:13.5px;line-height:1.4}
.toc a.lvl3{padding-left:26px;font-size:12.5px}
.toc a:hover{color:var(--ink)}
.toc a.active{color:var(--pat);border-left-color:var(--pat);font-weight:700}

/* ---------- Article (rendered markdown) ---------- */
.article{max-width:var(--readw);padding:34px 0 80px;min-width:0}
.article h1{font-size:30px;font-weight:840;letter-spacing:-.02em;margin:8px 0 18px}
.article h2{font-size:24px;font-weight:800;letter-spacing:-.01em;margin:52px 0 14px;padding-top:8px;scroll-margin-top:88px;position:relative}
.article h2::before{content:"";position:absolute;left:-18px;top:22px;width:7px;height:7px;border-radius:2px;background:var(--pat)}
.article h3{font-size:19px;font-weight:800;margin:34px 0 10px;scroll-margin-top:88px}
.article h4{font-size:16px;font-weight:800;margin:24px 0 8px;color:var(--slate)}
.article p{margin:0 0 16px}
.article ul,.article ol{margin:0 0 18px;padding-left:24px}
.article li{margin:6px 0}
.article li::marker{color:var(--pat)}
.article a.inline{color:var(--teal-d);font-weight:600;border-bottom:1px solid color-mix(in srgb,var(--teal-d) 40%,transparent)}
.article strong{font-weight:800;color:var(--ink)}
.article hr{border:none;border-top:1px solid var(--line);margin:36px 0}
.article blockquote{margin:20px 0;padding:14px 20px;background:color-mix(in srgb,var(--coral) 7%,var(--card));
  border-left:4px solid var(--coral);border-radius:0 12px 12px 0;color:var(--ink)}
.article blockquote p{margin:6px 0}
.article code{font-family:var(--mono);font-size:.86em;background:var(--bg-2);padding:2px 6px;border-radius:6px;color:var(--teal-d)}
/* code INSIDE a code block must not get the inline-code light pill */
.article pre code,.codeblock pre code{background:none;padding:0;border-radius:0;color:inherit;font-size:inherit}
.article table{width:100%;border-collapse:separate;border-spacing:0;margin:20px 0;font-size:14.5px;
  border:1px solid var(--line);border-radius:12px;overflow:hidden;display:block;overflow-x:auto}
.article thead th{background:var(--navy);color:#fff;font-weight:700;text-align:left;padding:11px 14px;white-space:nowrap}
.article tbody td{padding:10px 14px;border-top:1px solid var(--line);vertical-align:top}
.article tbody tr:nth-child(even){background:color-mix(in srgb,var(--bg-2) 55%,transparent)}
.article img{border-radius:14px;box-shadow:var(--shadow);margin:14px 0;border:1px solid var(--line)}
.article .imgcap{display:block;text-align:center;color:var(--slate);font-size:13px;margin:-6px 0 22px}

/* ---------- Code blocks + copy ---------- */
.codeblock{position:relative;margin:18px 0}
.codeblock pre{margin:0;background:#0e1729;color:#e6edf7;border-radius:12px;padding:16px 60px 16px 18px;
  white-space:pre-wrap;overflow-wrap:break-word;word-break:break-word;
  font-family:var(--mono);font-size:13.6px;line-height:1.7;border:1px solid #1c2942}
.codeblock.prompt pre{background:linear-gradient(180deg,#132038,#0e1729);border-color:#2a3a5c}
.codeblock .cbtag{position:absolute;top:-11px;left:14px;font-size:11px;font-weight:800;letter-spacing:.04em;
  background:var(--teal-d);color:#fff;padding:3px 10px;border-radius:999px}
.codeblock.prompt .cbtag{background:var(--coral)}
.copy{position:absolute;top:10px;right:10px;border:1px solid rgba(255,255,255,.18);background:rgba(255,255,255,.08);
  color:#cdd8ea;font-size:12px;font-weight:700;padding:6px 11px;border-radius:8px;cursor:pointer;transition:all .12s}
.copy:hover{background:var(--coral);color:#fff;border-color:transparent}
.copy.done{background:var(--teal-d);color:#fff;border-color:transparent}

/* ---------- Task list (interactive) ---------- */
.article ul.contains-task-list{list-style:none;padding-left:4px}
.article li.task-list-item{display:flex;gap:11px;align-items:flex-start;padding:9px 12px;border:1px solid var(--line);
  border-radius:10px;margin:8px 0;background:var(--card);transition:background .12s}
.article li.task-list-item:hover{background:var(--bg-2)}
.article li.task-list-item input{appearance:none;width:20px;height:20px;border:2px solid var(--slate);border-radius:6px;
  margin-top:2px;cursor:pointer;flex:none;position:relative;transition:all .12s}
.article li.task-list-item input:checked{background:var(--teal-d);border-color:var(--teal-d)}
.article li.task-list-item input:checked::after{content:"✓";position:absolute;inset:0;color:#fff;font-size:13px;font-weight:900;display:grid;place-items:center}
.article li.task-list-item.done{opacity:.62}
.article li.task-list-item.done label{text-decoration:line-through}

/* ---------- Prev/Next ---------- */
.pager{max-width:var(--readw);margin:0 auto;display:flex;gap:14px;padding:0 0 80px}
.pager a{flex:1;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px 20px;box-shadow:var(--shadow-sm);transition:transform .14s,box-shadow .14s}
.pager a:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.pager .dir{font-size:12px;color:var(--slate);font-weight:700}
.pager .ttl{font-weight:800;margin-top:3px}
.pager a.next{text-align:right}

/* ---------- Footer ---------- */
.foot{border-top:1px solid var(--line);background:var(--card);margin-top:20px}
.foot .wrap{max-width:var(--maxw);margin:0 auto;padding:34px 22px;color:var(--slate);font-size:13.5px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}

/* ---------- Progress bar (course) ---------- */
.progwrap{position:sticky;top:64px;z-index:40;height:3px;background:transparent}
.progbar{height:3px;background:linear-gradient(90deg,var(--coral),var(--teal));width:0}

/* ---------- Mobile ---------- */
.menutoggle{display:none}
@media (max-width:960px){
  .cards{grid-template-columns:1fr 1fr}
  .layout{grid-template-columns:1fr;gap:0}
  .side{position:fixed;left:0;top:0;bottom:0;width:280px;background:var(--card);z-index:60;transform:translateX(-102%);
    transition:transform .22s ease;box-shadow:var(--shadow-lg);padding:80px 20px 30px;max-height:100vh}
  .side.open{transform:none}
  .menutoggle{display:grid}
  .article{padding-top:22px}
  .scrim{position:fixed;inset:0;background:rgba(2,6,20,.5);z-index:55;opacity:0;pointer-events:none;transition:opacity .2s}
  .scrim.on{opacity:1;pointer-events:auto}
}
@media (max-width:640px){
  .cards{grid-template-columns:1fr}
  .tracks{grid-template-columns:1fr}
  .nav a.hideSm{display:none}
  .hero .wrap{padding:60px 22px 54px}
}