/* Devlish — design system
   Navy #0B1E3F base, gold #F5B841 accent. Dark, understated, technical. */

:root {
  --navy-900: #071429;
  --navy-800: #0B1E3F;
  --navy-700: #10294f;
  --navy-600: #17335f;
  --navy-500: #21406f;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --gold: #F5B841;
  --gold-dim: #d99f2e;
  --ink: #eaf0fb;
  --ink-soft: #b7c4dc;
  --ink-mute: #7f8fac;
  --green: #4ade80;
  --red: #f87171;
  --mono: ui-monospace, "SF Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --maxw: 1120px;
  --radius: 12px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--navy-800);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(1200px 600px at 80% -10%, rgba(245, 184, 65, 0.08), transparent 60%),
    radial-gradient(900px 500px at 0% 0%, rgba(33, 64, 111, 0.5), transparent 55%);
  background-attachment: fixed;
}

a { color: var(--gold); text-decoration: none; }
a:hover { color: var(--gold-dim); }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(7, 20, 41, 0.72);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; gap: 28px; height: 62px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -0.02em; color: var(--ink); font-size: 18px; }
.brand svg { display: block; }
.nav .spacer { flex: 1; }
.nav a.navlink { color: var(--ink-soft); font-size: 14.5px; font-weight: 500; }
.nav a.navlink:hover { color: var(--ink); }
@media (max-width: 720px) { .nav a.navlink.hide-sm { display: none; } }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--sans); font-size: 15px; font-weight: 600;
  padding: 11px 18px; border-radius: 10px; cursor: pointer;
  border: 1px solid transparent; transition: transform .06s ease, background .15s ease, border-color .15s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-gold { background: var(--gold); color: #241a03; }
.btn-gold:hover { background: #ffca57; color: #241a03; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--gold); color: var(--gold); }
.btn-run { background: var(--gold); color: #241a03; font-weight: 700; }
.btn-run:hover { background: #ffca57; }
.btn[disabled] { opacity: .55; cursor: default; }
.btn-sm { padding: 8px 13px; font-size: 13.5px; }

/* ---------- Hero ---------- */
.hero { padding: 72px 0 40px; }
.hero .eyebrow {
  display: inline-block; font-family: var(--mono); font-size: 12.5px; letter-spacing: .04em;
  color: var(--gold); border: 1px solid var(--line-strong); border-radius: 999px; padding: 5px 13px; margin-bottom: 22px;
}
.hero h1 {
  font-size: clamp(38px, 6vw, 62px); line-height: 1.02; letter-spacing: -0.03em; margin: 0 0 20px;
  font-weight: 800;
}
.hero h1 .accent { color: var(--gold); }
.hero p.lede { font-size: clamp(17px, 2.2vw, 20px); color: var(--ink-soft); max-width: 640px; margin: 0 0 28px; }
.hero .cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 10px; }
.hero .microcopy { color: var(--ink-mute); font-size: 13.5px; margin-top: 14px; }
.hero .microcopy code { color: var(--ink-soft); }

/* ---------- Playground ---------- */
.pg {
  border: 1px solid var(--line-strong); border-radius: var(--radius); overflow: hidden;
  background: var(--navy-900); box-shadow: 0 24px 60px rgba(0,0,0,0.4);
}
.pg-bar {
  display: flex; align-items: center; gap: 10px; padding: 10px 12px;
  background: linear-gradient(var(--navy-700), var(--navy-800)); border-bottom: 1px solid var(--line);
}
.pg-bar .dot { width: 11px; height: 11px; border-radius: 50%; }
.pg-bar .dot.r { background: #ff5f57; } .pg-bar .dot.y { background: #febc2e; } .pg-bar .dot.g { background: #28c840; }
.pg-bar .file { font-family: var(--mono); font-size: 12.5px; color: var(--ink-mute); margin-left: 6px; }
.pg-bar .spacer { flex: 1; }
.pg-select {
  font-family: var(--sans); font-size: 13px; color: var(--ink-soft);
  background: var(--navy-600); border: 1px solid var(--line-strong); border-radius: 8px; padding: 6px 10px; cursor: pointer;
}
.pg-body { display: grid; grid-template-columns: 1fr 1fr; min-height: 340px; }
@media (max-width: 860px) { .pg-body { grid-template-columns: 1fr; } }

.pg-editor-col { display: flex; flex-direction: column; border-right: 1px solid var(--line); }
@media (max-width: 860px) { .pg-editor-col { border-right: none; border-bottom: 1px solid var(--line); } }
.pg-editor {
  flex: 1; width: 100%; resize: vertical; min-height: 260px;
  font-family: var(--mono); font-size: 14px; line-height: 1.65;
  color: #e9eefc; background: var(--navy-900); border: 0; outline: none; padding: 16px 18px;
  tab-size: 2;
}
.pg-editor::selection { background: rgba(245,184,65,0.25); }

.pg-inputs {
  border-top: 1px solid var(--line); padding: 12px 16px; background: var(--navy-800);
  display: flex; flex-direction: column; gap: 9px;
}
.pg-inputs:empty { display: none; }
.pg-inputs .lbl { font-size: 11.5px; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-mute); }
.pg-input-row { display: flex; align-items: center; gap: 10px; }
.pg-input-row label { font-family: var(--mono); font-size: 12.5px; color: var(--gold); min-width: 130px; }
.pg-input-row input {
  flex: 1; font-family: var(--mono); font-size: 13px; color: var(--ink);
  background: var(--navy-900); border: 1px solid var(--line-strong); border-radius: 7px; padding: 7px 10px; outline: none;
}
.pg-input-row input:focus { border-color: var(--gold); }

.pg-output-col { display: flex; flex-direction: column; background: var(--navy-800); }
.pg-actions { display: flex; align-items: center; gap: 10px; padding: 12px 16px; border-bottom: 1px solid var(--line); }
.pg-actions .spacer { flex: 1; }
.pg-status { font-family: var(--mono); font-size: 12px; color: var(--ink-mute); }
.pg-status.ok { color: var(--green); } .pg-status.err { color: var(--red); }

.pg-console {
  flex: 1; margin: 0; padding: 16px 18px; overflow: auto; min-height: 200px;
  font-family: var(--mono); font-size: 13px; line-height: 1.7; color: var(--ink-soft);
}
.pg-console .out { color: #eaf6ff; }
.pg-console .out::before { content: "› "; color: var(--gold); }
.pg-console .diag { color: var(--red); white-space: pre-wrap; }
.pg-console .file-w { color: var(--ink-mute); }
.pg-console .file-w b { color: var(--ink-soft); font-weight: 600; }
.pg-console .hint { color: var(--ink-mute); }
.pg-console .trace-toggle { color: var(--gold); cursor: pointer; font-size: 12px; }
.pg-console .trace { margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--line); color: var(--ink-mute); font-size: 11.5px; }

/* ---------- Sections ---------- */
section.band { padding: 76px 0; border-top: 1px solid var(--line); }
.section-head { max-width: 640px; margin-bottom: 40px; }
.section-head .kicker { font-family: var(--mono); font-size: 12.5px; letter-spacing: .06em; color: var(--gold); text-transform: uppercase; }
.section-head h2 { font-size: clamp(27px, 3.6vw, 38px); letter-spacing: -0.02em; margin: 12px 0 12px; line-height: 1.1; }
.section-head p { color: var(--ink-soft); font-size: 17px; margin: 0; }

/* value props */
.props { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
@media (max-width: 860px) { .props { grid-template-columns: 1fr; } }
.prop { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; background: rgba(16, 41, 79, 0.35); }
.prop h3 { margin: 14px 0 8px; font-size: 18px; letter-spacing: -0.01em; }
.prop p { margin: 0; color: var(--ink-soft); font-size: 15px; }
.prop .ic { width: 34px; height: 34px; color: var(--gold); }

/* use cases */
.cases { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
@media (max-width: 760px) { .cases { grid-template-columns: 1fr; } }
.case {
  border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 22px 18px; background: rgba(7,20,41,0.4);
  display: flex; flex-direction: column; gap: 8px; transition: border-color .15s ease;
}
.case:hover { border-color: var(--line-strong); }
.case h3 { margin: 0; font-size: 17px; }
.case p { margin: 0; color: var(--ink-soft); font-size: 14.5px; flex: 1; }
.case a.try { font-size: 13.5px; font-family: var(--mono); margin-top: 6px; }
.case a.try::after { content: " →"; }

/* comparison table */
.cmp-scroll { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table.cmp { width: 100%; border-collapse: collapse; min-width: 680px; font-size: 14.5px; }
table.cmp th, table.cmp td { text-align: left; padding: 14px 16px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.cmp thead th { font-size: 13px; color: var(--ink-mute); font-weight: 600; text-transform: uppercase; letter-spacing: .04em; }
table.cmp thead th.devlish { color: var(--gold); }
table.cmp td.feat { color: var(--ink); font-weight: 600; }
table.cmp td.devlish { color: var(--ink); background: rgba(245,184,65,0.06); }
table.cmp td .yes { color: var(--green); } table.cmp td .no { color: var(--red); } table.cmp td .mid { color: var(--gold); }
table.cmp tr:last-child td { border-bottom: 0; }

/* course */
.course-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 40px; align-items: center; }
@media (max-width: 860px) { .course-grid { grid-template-columns: 1fr; } }
.modules { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
@media (max-width: 520px) { .modules { grid-template-columns: 1fr; } }
.mod { display: flex; gap: 11px; align-items: flex-start; border: 1px solid var(--line); border-radius: 10px; padding: 12px 13px; background: rgba(16,41,79,0.3); }
.mod .n { font-family: var(--mono); font-size: 12px; color: var(--gold); border: 1px solid var(--line-strong); border-radius: 6px; width: 26px; height: 26px; display: grid; place-items: center; flex: none; }
.mod .t { font-size: 13.5px; color: var(--ink-soft); line-height: 1.35; }

/* origin / callout */
.origin { border: 1px solid var(--line); border-left: 3px solid var(--gold); border-radius: var(--radius); padding: 30px 32px; background: rgba(7,20,41,0.5); }
.origin p { font-size: 17px; color: var(--ink-soft); margin: 0 0 12px; }
.origin p:last-child { margin-bottom: 0; }
.origin .who { font-size: 14px; color: var(--ink-mute); }

/* status list */
.status-list { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.status-list .chip { font-family: var(--mono); font-size: 12.5px; color: var(--ink-soft); border: 1px solid var(--line); border-radius: 999px; padding: 6px 13px; background: rgba(16,41,79,0.35); }
.status-list .chip b { color: var(--gold); font-weight: 600; }

/* newsletter */
.news { text-align: center; }
.news form { display: flex; gap: 10px; max-width: 460px; margin: 22px auto 0; }
@media (max-width: 520px) { .news form { flex-direction: column; } }
.news input {
  flex: 1; font-family: var(--sans); font-size: 15px; color: var(--ink);
  background: var(--navy-900); border: 1px solid var(--line-strong); border-radius: 10px; padding: 12px 14px; outline: none;
}
.news input:focus { border-color: var(--gold); }
.news .note { color: var(--ink-mute); font-size: 12.5px; margin-top: 10px; }

/* footer */
footer.foot { border-top: 1px solid var(--line); padding: 40px 0; color: var(--ink-mute); font-size: 14px; }
footer.foot .wrap { display: flex; flex-wrap: wrap; gap: 20px; align-items: center; }
footer.foot .spacer { flex: 1; }
footer.foot a { color: var(--ink-soft); }
footer.foot a:hover { color: var(--gold); }

/* code highlight (static snippets) */
pre.code { margin: 0; font-family: var(--mono); font-size: 13.5px; line-height: 1.7; color: #e9eefc; overflow-x: auto; }
.code-sample { background: var(--navy-900); border: 1px solid var(--line-strong); border-radius: var(--radius); padding: 20px 24px; margin: 1.5rem auto 0; max-width: 640px; font-family: var(--mono); font-size: 13.5px; line-height: 1.7; color: #e9eefc; overflow-x: auto; }
.embed-details { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1.25rem; margin-top: 2rem; max-width: 740px; margin-left: auto; margin-right: auto; }
.embed-point { display: flex; flex-direction: column; gap: 4px; }
.embed-point b { color: var(--gold); font-size: 0.95rem; }
.embed-point span { color: var(--ink-soft); font-size: 0.88rem; line-height: 1.5; }

/* embed detail page */
.prose { max-width: 720px; margin: 0 auto; }
.prose h2 { color: var(--ink); margin-top: 2.5rem; margin-bottom: 0.75rem; }
.prose h3 { color: var(--gold); margin-top: 2rem; margin-bottom: 0.5rem; font-size: 1.05rem; }
.prose p { color: var(--ink-soft); line-height: 1.7; margin-bottom: 1rem; }
.prose ul, .prose ol { color: var(--ink-soft); line-height: 1.7; padding-left: 1.5rem; }
.prose li { margin-bottom: 0.5rem; }
.prose li b { color: var(--ink); }
.prose a { color: var(--gold); text-decoration: underline; text-underline-offset: 2px; }
.prose code { background: rgba(245,184,65,0.08); padding: 2px 6px; border-radius: 4px; font-size: 0.88em; }
.prose .code-sample { text-align: left; }
.steps { list-style: none; padding: 0; counter-reset: step; }
.steps li { margin-bottom: 2rem; }
.steps li b { display: block; color: var(--ink); font-size: 1rem; margin-bottom: 0.5rem; }
.compat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin-top: 1rem; }
.compat-item { padding: 1rem; border: 1px solid var(--line); border-radius: 8px; }
.compat-item b { display: block; color: var(--ink); margin-bottom: 4px; }
.compat-item span { color: var(--ink-soft); font-size: 0.85rem; line-height: 1.4; }
.arch-diagram { margin: 1.5rem 0; }
.arch-step { display: flex; gap: 1rem; align-items: flex-start; padding: 1rem; border: 1px solid var(--line); border-radius: 8px; margin-bottom: 0.5rem; }
.arch-step p { margin: 0.25rem 0 0; font-size: 0.88rem; }
.arch-num { display: flex; align-items: center; justify-content: center; width: 28px; height: 28px; min-width: 28px; border-radius: 50%; background: var(--gold); color: var(--navy-900); font-weight: 700; font-size: 0.85rem; }
.arch-arrow { text-align: center; color: var(--ink-mute); font-size: 1.2rem; margin: 0.25rem 0; }
.detail-table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
.detail-table td { padding: 0.75rem 1rem; border: 1px solid var(--line); color: var(--ink-soft); font-size: 0.9rem; line-height: 1.5; vertical-align: top; }
.detail-table td:first-child { width: 160px; white-space: nowrap; }
.detail-table td b { color: var(--ink); }

.tok-kw { color: var(--gold); }
.tok-str { color: #7fd9a6; }
.tok-num { color: #6fb2ff; }
.tok-com { color: var(--ink-mute); font-style: italic; }

/* ---------- Lesson pages ---------- */
.lesson-head { padding: 56px 0 8px; }
.lesson-head .crumb { font-family: var(--mono); font-size: 13px; color: var(--ink-mute); margin-bottom: 16px; }
.lesson-head .crumb a { color: var(--ink-soft); }
.lesson-head .modtag { font-family: var(--mono); font-size: 12.5px; letter-spacing: .05em; color: var(--gold); text-transform: uppercase; }
.lesson-head h1 { font-size: clamp(30px, 4.5vw, 46px); letter-spacing: -0.025em; line-height: 1.05; margin: 12px 0 14px; }
.lesson-head p.sub { font-size: clamp(17px, 2.2vw, 20px); color: var(--ink-soft); max-width: 640px; margin: 0; }

.progress-rail { display: flex; gap: 6px; margin-top: 24px; flex-wrap: wrap; }
.progress-rail a { width: 30px; height: 6px; border-radius: 999px; background: var(--navy-500); transition: background .15s ease; }
.progress-rail a:hover { background: var(--gold-dim); }
.progress-rail a.done { background: var(--gold-dim); }
.progress-rail a.current { background: var(--gold); }

.prose { max-width: 680px; }
.prose p { font-size: 17px; color: var(--ink-soft); margin: 0 0 18px; }
.prose p strong, .prose strong { color: var(--ink); font-weight: 600; }
.prose h2 { font-size: 22px; letter-spacing: -0.01em; margin: 34px 0 14px; }
.prose code.inl { font-family: var(--mono); font-size: 0.92em; color: var(--gold); background: rgba(245,184,65,0.08); padding: 1px 6px; border-radius: 5px; }

.key-ideas { display: flex; flex-wrap: wrap; gap: 8px; margin: 6px 0 26px; }
.key-ideas .ki { font-family: var(--mono); font-size: 12.5px; color: var(--ink-soft); border: 1px solid var(--line); border-radius: 999px; padding: 6px 13px; background: rgba(16,41,79,0.35); }

.try-section { margin: 32px 0 8px; }
.try-section .try-label { font-family: var(--mono); font-size: 12.5px; letter-spacing: .05em; text-transform: uppercase; color: var(--gold); margin-bottom: 10px; }
.try-section .pg { box-shadow: 0 16px 40px rgba(0,0,0,0.32); }

.codecard { border: 1px solid var(--line-strong); border-radius: var(--radius); overflow: hidden; background: var(--navy-900); }
.codecard .cc-bar { display: flex; align-items: center; gap: 8px; padding: 9px 14px; background: linear-gradient(var(--navy-700), var(--navy-800)); border-bottom: 1px solid var(--line); }
.codecard .cc-bar .file { font-family: var(--mono); font-size: 12.5px; color: var(--ink-mute); }
.codecard pre.code { padding: 16px 18px; }
.codecard .cc-note { border-top: 1px solid var(--line); padding: 12px 16px; font-size: 13.5px; color: var(--ink-mute); background: rgba(16,41,79,0.3); }
.codecard .cc-note b { color: var(--gold); font-weight: 600; }

.lesson-nav { display: flex; gap: 14px; margin: 48px 0 0; }
.lesson-nav a { flex: 1; border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; display: flex; flex-direction: column; gap: 3px; transition: border-color .15s ease; }
.lesson-nav a:hover { border-color: var(--gold); }
.lesson-nav a .dir { font-family: var(--mono); font-size: 12px; color: var(--ink-mute); }
.lesson-nav a .ttl { color: var(--ink); font-weight: 600; font-size: 15px; }
.lesson-nav a.next { text-align: right; }
.lesson-nav a.disabled { opacity: .4; pointer-events: none; }
@media (max-width: 560px) { .lesson-nav { flex-direction: column; } .lesson-nav a.next { text-align: left; } }

/* full playground page */
body.playground-page { display: flex; flex-direction: column; min-height: 100vh; }
.pg-full { flex: 1; display: flex; flex-direction: column; padding: 24px; }
.pg-full .pg { flex: 1; display: flex; flex-direction: column; }
.pg-full .pg-body { flex: 1; }
.pg-full .pg-editor { min-height: 380px; }