/* ══════════════════════════════════════════════════════════
   VikStack — shared design system
   Used by every page. Page-specific styles stay inline.
   ══════════════════════════════════════════════════════════ */
:root {
  --bg: #08090D; --bg-2: #0C0F16; --surface: #10141C; --surface-2: #141922;
  --border: #1E2530; --border-hi: #2A3342;
  --text-hi: #EDF1F7; --text: #A5B0C0; --text-mid: #7A8698; --text-low: #4C5666;
  --indigo: #6366F1; --blue: #3B82F6; --cyan: #38BDF8; --emerald: #2EE59D;
  --purple: #A78BFA; --pink: #F472B6; --orange: #FB923C;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, monospace;
  --r: 16px; --maxw: 1200px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { background: var(--bg); color: var(--text); font-family: var(--sans); line-height: 1.6; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
a { color: inherit; text-decoration: none; }
::selection { background: rgba(46,229,157,.25); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }
.eyebrow { font-family: var(--mono); font-size: 12.5px; font-weight: 500; letter-spacing: 1px; text-transform: uppercase; color: var(--emerald); }
.muted { color: var(--text-mid); }

/* ambient bg */
.bg-fx { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; }
.bg-fx .grid { position: absolute; inset: 0; background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px); background-size: 64px 64px; opacity: .4; mask-image: radial-gradient(ellipse 100% 60% at 50% -10%, #000 30%, transparent 75%); -webkit-mask-image: radial-gradient(ellipse 100% 60% at 50% -10%, #000 30%, transparent 75%); }
.bg-fx .glow { position: absolute; top: -320px; left: 50%; transform: translateX(-50%); width: 900px; height: 700px; background: radial-gradient(circle at 50% 40%, rgba(56,189,248,.14), rgba(46,229,157,.06) 40%, transparent 70%); filter: blur(20px); }

/* nav */
header.nav { position: sticky; top: 0; z-index: 50; backdrop-filter: saturate(140%) blur(14px); -webkit-backdrop-filter: saturate(140%) blur(14px); background: rgba(8,9,13,.72); border-bottom: 1px solid var(--border); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.brand { display: flex; align-items: center; gap: 9px; font-family: var(--mono); font-size: 19px; font-weight: 700; letter-spacing: -.5px; color: var(--text-hi); }
.brand .b { color: var(--blue); }
.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-menu a { font-size: 14px; font-weight: 500; color: var(--text); padding: 8px 13px; border-radius: 9px; transition: color .16s, background .16s; }
.nav-menu a:hover, .nav-menu a.active { color: var(--text-hi); background: var(--surface); }
.nav-right { display: flex; align-items: center; gap: 10px; }
.nav-toggle { display: none; width: 40px; height: 40px; align-items: center; justify-content: center; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; cursor: pointer; color: var(--text-hi); }
.nav-toggle svg { width: 20px; height: 20px; }

/* ── mega-menu ── */
.nav-group { position: relative; }
.nav-trigger { display: inline-flex; align-items: center; gap: 6px; font-family: var(--sans); font-size: 14px; font-weight: 500; color: var(--text); background: none; border: none; padding: 8px 13px; border-radius: 9px; cursor: pointer; transition: color .16s, background .16s; }
.nav-group:hover .nav-trigger, .nav-group.active .nav-trigger { color: var(--text-hi); background: var(--surface); }
.nav-trigger .chev { width: 13px; height: 13px; transition: transform .2s; opacity: .7; }
.nav-group:hover .chev { transform: rotate(180deg); }
.mega { position: absolute; top: 100%; left: 0; padding-top: 10px; min-width: 440px; opacity: 0; visibility: hidden; transform: translateY(6px); transition: opacity .16s ease, transform .16s ease, visibility .16s; z-index: 60; }
.nav-group:hover .mega, .nav-group:focus-within .mega { opacity: 1; visibility: visible; transform: none; }
.mega-inner { background: rgba(14,18,25,.98); backdrop-filter: saturate(140%) blur(16px); -webkit-backdrop-filter: saturate(140%) blur(16px); border: 1px solid var(--border-hi); border-radius: 16px; padding: 10px; box-shadow: 0 30px 70px -25px rgba(0,0,0,.85); display: grid; gap: 4px; }
.mega-tile { display: flex; gap: 13px; align-items: flex-start; padding: 12px; border-radius: 11px; transition: background .14s; }
.mega-tile:hover { background: var(--surface); }
.mega-tile .mi { width: 38px; height: 38px; border-radius: 10px; display: flex; align-items: center; justify-content: center; border: 1px solid var(--border-hi); background: var(--surface-2); color: var(--c, var(--cyan)); flex-shrink: 0; }
.mega-tile .mi svg { width: 19px; height: 19px; }
.mega-tile h6 { font-size: 14px; font-weight: 600; color: var(--text-hi); }
.mega-tile p { font-size: 12.5px; color: var(--text-mid); margin-top: 2px; line-height: 1.45; }
.mega-tile.feat { background: linear-gradient(120deg, rgba(56,189,248,.09), rgba(46,229,157,.05)); border: 1px solid rgba(56,189,248,.2); }
.nav-mobile { display: none; }

/* ── command palette (⌘K) ── */
.cmdk-overlay { position: fixed; inset: 0; z-index: 200; background: rgba(4,6,10,.7); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); display: none; align-items: flex-start; justify-content: center; padding: 13vh 20px 20px; }
.cmdk-overlay.open { display: flex; }
.cmdk { width: 100%; max-width: 560px; background: rgba(16,20,28,.99); border: 1px solid var(--border-hi); border-radius: 16px; overflow: hidden; box-shadow: 0 40px 90px -30px rgba(0,0,0,.9); }
.cmdk-top { display: flex; align-items: center; gap: 12px; padding: 4px 18px; border-bottom: 1px solid var(--border); }
.cmdk-top svg { width: 18px; height: 18px; color: var(--text-low); flex-shrink: 0; }
.cmdk-input { flex: 1; background: none; border: none; color: var(--text-hi); font-size: 16px; padding: 17px 0; outline: none; font-family: var(--sans); }
.cmdk-input::placeholder { color: var(--text-low); }
.cmdk-esc { font-family: var(--mono); font-size: 11px; color: var(--text-low); border: 1px solid var(--border); border-radius: 6px; padding: 3px 7px; }
.cmdk-list { max-height: 344px; overflow-y: auto; padding: 8px; }
.cmdk-item { display: flex; align-items: center; gap: 12px; padding: 11px 13px; border-radius: 10px; cursor: pointer; }
.cmdk-item .ci { width: 32px; height: 32px; border-radius: 8px; display: flex; align-items: center; justify-content: center; border: 1px solid var(--border-hi); background: var(--surface-2); color: var(--c, var(--cyan)); flex-shrink: 0; }
.cmdk-item .ci svg { width: 16px; height: 16px; }
.cmdk-item .ct { font-size: 14px; font-weight: 500; color: var(--text-hi); }
.cmdk-item .csub { font-size: 12px; color: var(--text-mid); }
.cmdk-item .cgo { margin-left: auto; font-family: var(--mono); font-size: 11px; color: var(--text-low); }
.cmdk-item.active, .cmdk-item:hover { background: var(--surface); }
.cmdk-empty { padding: 28px; text-align: center; color: var(--text-mid); font-size: 14px; }
.kbd { display: inline-flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 12.5px; color: var(--text-mid); background: var(--surface); border: 1px solid var(--border); border-radius: 9px; padding: 7px 11px; transition: border-color .16s; cursor: pointer; }
.kbd:hover { border-color: var(--border-hi); }
.kbd .keys { color: var(--text-low); }

.btn { display: inline-flex; align-items: center; gap: 7px; font-size: 14px; font-weight: 600; border-radius: 10px; padding: 9px 16px; transition: transform .12s, box-shadow .18s, background .16s, border-color .16s; cursor: pointer; border: 1px solid transparent; }
.btn-primary { background: linear-gradient(180deg, #4DC9F5, var(--blue)); color: #04121f; font-weight: 700; }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 10px 30px -8px rgba(56,189,248,.5); }
.btn-ghost { background: var(--surface); border-color: var(--border); color: var(--text-hi); }
.btn-ghost:hover { border-color: var(--border-hi); background: var(--surface-2); }
.btn-lg { padding: 14px 24px; font-size: 15.5px; border-radius: 12px; }

/* section shell */
section.blk { position: relative; z-index: 1; padding: 92px 0; }
.head { max-width: 640px; margin-bottom: 46px; }
.head.center { margin-left: auto; margin-right: auto; text-align: center; }
.head h2 { font-size: clamp(28px, 3.8vw, 42px); font-weight: 800; letter-spacing: -1.2px; color: var(--text-hi); margin-top: 14px; line-height: 1.1; }
.head p { font-size: 17px; color: var(--text); margin-top: 14px; }

/* page header (interior pages) */
.page-head { position: relative; z-index: 1; padding: 72px 0 20px; text-align: center; }
.page-head h1 { font-size: clamp(34px, 5vw, 56px); font-weight: 800; letter-spacing: -1.8px; color: var(--text-hi); margin-top: 16px; line-height: 1.04; }
.page-head h1 .grad { background: linear-gradient(110deg, var(--cyan), var(--emerald)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.page-head p.lead { font-size: clamp(16px, 2vw, 19px); color: var(--text); max-width: 600px; margin: 20px auto 0; }

/* chips (category filters) */
.chips { display: flex; flex-wrap: wrap; gap: 9px; justify-content: center; margin-top: 34px; }
.chip { font-size: 13.5px; font-weight: 500; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 999px; padding: 8px 16px; cursor: pointer; transition: all .16s; }
.chip:hover { border-color: var(--border-hi); color: var(--text-hi); }
.chip.active { background: rgba(46,229,157,.1); border-color: rgba(46,229,157,.35); color: var(--emerald); }

/* forms / newsletter band */
.capture { max-width: 470px; margin: 0 auto; }
.form-row { display: flex; gap: 10px; }
.form-row input { flex: 1; background: var(--bg-2); border: 1px solid var(--border-hi); color: var(--text-hi); font-family: var(--sans); font-size: 15px; padding: 14px 16px; border-radius: 12px; outline: none; transition: border-color .16s; }
.form-row input::placeholder { color: var(--text-low); }
.form-row input:focus { border-color: var(--cyan); }
.form-note { font-size: 13px; color: var(--text-low); margin-top: 13px; }
.form-success { display: none; color: var(--emerald); font-size: 16px; font-weight: 600; padding: 16px; }
.nl { position: relative; overflow: hidden; background: linear-gradient(160deg, #0F1A24, #0A0E14); border: 1px solid var(--border-hi); border-radius: 24px; padding: 56px 40px; text-align: center; }
.nl::before { content: ""; position: absolute; top: -140px; left: 50%; transform: translateX(-50%); width: 640px; height: 400px; background: radial-gradient(circle, rgba(56,189,248,.16), transparent 65%); }
.nl > * { position: relative; }
.nl h2 { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; letter-spacing: -1px; color: var(--text-hi); }
.nl p { font-size: 16.5px; color: var(--text); max-width: 480px; margin: 14px auto 32px; }

/* footer */
footer.site { position: relative; z-index: 1; border-top: 1px solid var(--border); padding: 64px 0 40px; margin-top: 40px; }
.foot-grid { display: grid; grid-template-columns: 1.6fr repeat(4, 1fr); gap: 40px; }
.foot-brand .brand { margin-bottom: 14px; }
.foot-brand p { font-size: 14px; color: var(--text-mid); max-width: 260px; }
.foot-col h5 { font-size: 12px; font-family: var(--mono); text-transform: uppercase; letter-spacing: .8px; color: var(--text-low); margin-bottom: 16px; }
.foot-col a { display: block; font-size: 14px; color: var(--text); padding: 6px 0; transition: color .15s; }
.foot-col a:hover { color: var(--text-hi); }
.foot-bottom { display: flex; justify-content: space-between; align-items: center; margin-top: 52px; padding-top: 26px; border-top: 1px solid var(--border); flex-wrap: wrap; gap: 14px; }
.foot-bottom p { font-size: 13px; color: var(--text-low); }
.socials { display: flex; gap: 8px; }
.socials a { width: 38px; height: 38px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface); display: flex; align-items: center; justify-content: center; transition: border-color .16s, transform .16s; }
.socials a:hover { border-color: var(--border-hi); transform: translateY(-2px); }
.socials svg { width: 18px; height: 18px; }

/* reveal */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s cubic-bezier(.2,.7,.2,1), transform .6s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity: 1; transform: none; }

/* ── MailerLite embedded forms → brand them everywhere (email capture) ── */
.ml-embedded { min-height: 76px; }
.ml-form-embedContainer, .ml-form-embedWrapper, .ml-form-embedBody,
.ml-form-successBody, .ml-form-embedContent, .ml-form-successContent, .ml-form-formContent {
  background: transparent !important; box-shadow: none !important; border: 0 !important;
  max-width: 100% !important; padding: 0 !important; margin: 0 auto !important;
}
.ml-form-embedContent { display: none !important; }
.ml-form-successContent h1, .ml-form-successContent h4 { color: var(--text-hi) !important; font-family: var(--sans) !important; font-weight: 800 !important; }
.ml-form-successContent p { color: var(--text) !important; font-family: var(--sans) !important; }
.ml-form-embedBody { padding: 4px 2px 2px !important; }
.ml-form-fieldRow, .ml-form-horizontalRow { margin-bottom: 12px !important; }
html body .ml-form-embedBody input, html body .ml-embedded input[type="email"], html body .ml-embedded input[type="text"] {
  background: var(--bg-2) !important; background-color: var(--bg-2) !important;
  border: 1px solid var(--border-hi) !important; color: var(--text-hi) !important;
  -webkit-text-fill-color: var(--text-hi) !important; border-radius: 12px !important;
  padding: 14px 16px !important; font-size: 15px !important; font-family: var(--sans) !important;
  width: 100% !important; box-shadow: none !important;
}
html body .ml-embedded input::placeholder { color: var(--text-low) !important; -webkit-text-fill-color: var(--text-low) !important; }
html body .ml-embedded input:focus { border-color: var(--cyan) !important; outline: none !important; }
.ml-form-embedSubmit button, .ml-embedded button[type="submit"], .ml-form-embedSubmit .primary {
  background: linear-gradient(180deg, #4DC9F5, var(--blue)) !important; color: #04121f !important;
  border: 0 !important; border-radius: 12px !important; font-weight: 700 !important; font-size: 15px !important;
  font-family: var(--sans) !important; padding: 14px !important; width: 100% !important;
  box-shadow: 0 10px 26px rgba(56,189,248,.28) !important; cursor: pointer !important;
}
.ml-form-embedSubmit button:hover { filter: brightness(1.06); }
.ml-form-embedSubmit button.loading { background: var(--surface-2) !important; }

/* diagram cards (shared with library) */
.diagrams { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.diagram { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r); overflow: hidden; transition: border-color .18s, transform .18s; cursor: pointer; }
.diagram:hover { border-color: var(--border-hi); transform: translateY(-3px); }
.diagram .thumb { height: 158px; position: relative; background: radial-gradient(120% 120% at 50% 0%, var(--surface-2), var(--bg-2)); border-bottom: 1px solid var(--border); overflow: hidden; }
.diagram .thumb::before { content: ""; position: absolute; inset: 0; background-image: radial-gradient(var(--border-hi) 1px, transparent 1px); background-size: 20px 20px; opacity: .4; }
.mini-node { position: absolute; font-family: var(--mono); font-size: 10.5px; color: var(--text-hi); background: var(--surface-2); border: 1px solid var(--border-hi); border-radius: 7px; padding: 5px 8px; }
.diagram .meta { padding: 16px 18px; }
.diagram .cat { font-family: var(--mono); font-size: 11px; text-transform: uppercase; letter-spacing: .6px; color: var(--c, var(--cyan)); }
.diagram h4 { font-size: 16px; font-weight: 700; color: var(--text-hi); margin-top: 7px; letter-spacing: -.2px; }
.diagram .sub { font-size: 13px; color: var(--text-mid); margin-top: 4px; }

/* ── generic grids ── */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }

/* ── generic card ── */
.card { background: linear-gradient(180deg, var(--surface), var(--bg-2)); border: 1px solid var(--border); border-radius: var(--r); padding: 24px; transition: border-color .18s, transform .18s; }
.card:hover { border-color: var(--border-hi); transform: translateY(-3px); }

/* ── tool cards ── */
.tool-card { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 22px; transition: border-color .18s, transform .18s; overflow: hidden; }
.tool-card:hover { border-color: var(--border-hi); transform: translateY(-3px); }
.tool-card .ti { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; border: 1px solid var(--border-hi); color: var(--c, var(--cyan)); background: var(--surface-2); margin-bottom: 15px; }
.tool-card .ti svg { width: 20px; height: 20px; }
.tool-card h4 { font-size: 16px; font-weight: 700; color: var(--text-hi); letter-spacing: -.2px; }
.tool-card p { font-size: 13.5px; color: var(--text-mid); margin-top: 6px; }
.tool-card .badge { display: inline-block; margin-top: 14px; font-family: var(--mono); font-size: 10.5px; color: var(--c, var(--cyan)); background: color-mix(in srgb, var(--c, var(--cyan)) 10%, transparent); border: 1px solid color-mix(in srgb, var(--c, var(--cyan)) 25%, transparent); border-radius: 6px; padding: 3px 8px; }
.badge-soon { color: var(--text-mid) !important; background: var(--surface-2) !important; border-color: var(--border) !important; }

/* ── pricing ── */
.pricing { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; align-items: start; }
.price-card { background: linear-gradient(180deg, var(--surface), var(--bg-2)); border: 1px solid var(--border); border-radius: 20px; padding: 32px; position: relative; transition: border-color .18s, transform .18s; }
.price-card:hover { border-color: var(--border-hi); transform: translateY(-3px); }
.price-card.feat { border-color: rgba(56,189,248,.4); box-shadow: 0 20px 60px -30px rgba(56,189,248,.4); }
.price-card .tag { position: absolute; top: -12px; left: 32px; font-family: var(--mono); font-size: 11px; font-weight: 600; color: #04121f; background: linear-gradient(180deg, #4DC9F5, var(--blue)); border-radius: 999px; padding: 5px 12px; }
.price-card .pname { font-size: 14px; font-family: var(--mono); text-transform: uppercase; letter-spacing: .8px; color: var(--text-mid); }
.price-card .amt { font-size: 40px; font-weight: 900; letter-spacing: -1.5px; color: var(--text-hi); margin: 12px 0 4px; }
.price-card .amt .old { font-size: 20px; color: var(--text-low); text-decoration: line-through; font-weight: 600; margin-left: 8px; }
.price-card .pdesc { font-size: 14px; color: var(--text-mid); margin-bottom: 22px; }
.price-card ul { list-style: none; margin-bottom: 26px; }
.price-card li { font-size: 14px; color: var(--text); padding: 8px 0 8px 26px; position: relative; }
.price-card li::before { content: "✓"; position: absolute; left: 0; color: var(--emerald); font-weight: 800; }
.price-card .btn { width: 100%; justify-content: center; }

/* ── FAQ ── */
.faq { max-width: 760px; margin: 0 auto; }
.faq-item { border: 1px solid var(--border); border-radius: 14px; margin-bottom: 12px; background: var(--surface); overflow: hidden; }
.faq-q { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 20px 22px; cursor: pointer; font-size: 16px; font-weight: 600; color: var(--text-hi); list-style: none; }
.faq-q::-webkit-details-marker { display: none; }
.faq-q .ar { color: var(--text-low); transition: transform .2s; flex-shrink: 0; }
.faq-item[open] .faq-q .ar { transform: rotate(45deg); }
.faq-a { padding: 0 22px 20px; font-size: 15px; color: var(--text-mid); }

/* ── question cards (interview) ── */
.q-card { display: flex; align-items: center; gap: 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 13px; padding: 18px 20px; transition: border-color .18s, transform .18s; }
.q-card:hover { border-color: var(--border-hi); transform: translateX(3px); }
.q-card .qn { font-family: var(--mono); font-size: 13px; color: var(--text-low); flex-shrink: 0; width: 30px; }
.q-card .qt { font-size: 15px; font-weight: 600; color: var(--text-hi); flex: 1; }
.q-card .ql { font-family: var(--mono); font-size: 11px; padding: 4px 9px; border-radius: 6px; border: 1px solid var(--border-hi); }
.ql.easy { color: var(--emerald); } .ql.med { color: var(--orange); } .ql.hard { color: var(--pink); }

/* ── roadmap tree ── */
.rm-tree { max-width: 620px; margin: 0 auto; }
.rm-node { display: flex; gap: 16px; align-items: flex-start; padding: 8px 0; position: relative; }
.rm-node .num { width: 38px; height: 38px; flex-shrink: 0; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-family: var(--mono); font-size: 14px; font-weight: 700; border: 1px solid var(--border-hi); background: var(--surface-2); color: var(--text-hi); z-index: 1; }
.rm-node.done .num { background: rgba(46,229,157,.14); border-color: var(--emerald); color: var(--emerald); }
.rm-node:not(:last-child)::after { content: ""; position: absolute; left: 19px; top: 40px; bottom: -8px; width: 1.5px; background: var(--border-hi); }
.rm-card { flex: 1; background: var(--surface); border: 1px solid var(--border); border-radius: 13px; padding: 16px 20px; margin-bottom: 8px; transition: border-color .18s; }
.rm-card:hover { border-color: var(--border-hi); }
.rm-card h4 { font-size: 15.5px; font-weight: 700; color: var(--text-hi); }
.rm-card p { font-size: 13px; color: var(--text-mid); margin-top: 4px; }
.rm-card .tags { margin-top: 10px; display: flex; gap: 7px; flex-wrap: wrap; }
.rm-card .rt { font-family: var(--mono); font-size: 10.5px; color: var(--text); background: var(--surface-2); border: 1px solid var(--border); border-radius: 6px; padding: 3px 8px; }

/* ── article cards ── */
.articles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.art { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r); padding: 24px; transition: border-color .18s, transform .18s; display: flex; flex-direction: column; }
.art:hover { border-color: var(--border-hi); transform: translateY(-3px); }
.art .cat { font-family: var(--mono); font-size: 11px; text-transform: uppercase; letter-spacing: .6px; color: var(--c, var(--cyan)); }
.art h4 { font-size: 18px; font-weight: 700; color: var(--text-hi); margin: 10px 0; letter-spacing: -.3px; line-height: 1.3; }
.art p { font-size: 14px; color: var(--text-mid); flex: 1; }
.art .foot { margin-top: 18px; font-size: 12.5px; color: var(--text-low); font-family: var(--mono); display: flex; gap: 12px; }
.art-feat { display: grid; grid-template-columns: 1.1fr 1fr; gap: 0; background: linear-gradient(180deg, var(--surface), var(--bg-2)); border: 1px solid var(--border); border-radius: 20px; overflow: hidden; margin-bottom: 24px; }
.art-feat:hover { border-color: var(--border-hi); }
.art-feat .vis { position: relative; background: radial-gradient(120% 120% at 30% 0%, var(--surface-2), var(--bg-2)); border-right: 1px solid var(--border); min-height: 260px; overflow: hidden; }
.art-feat .vis::before { content: ""; position: absolute; inset: 0; background-image: radial-gradient(var(--border-hi) 1px, transparent 1px); background-size: 22px 22px; opacity: .4; }
.art-feat .body { padding: 40px; display: flex; flex-direction: column; justify-content: center; }
.art-feat .body h3 { font-size: 26px; font-weight: 800; color: var(--text-hi); letter-spacing: -.6px; line-height: 1.15; margin: 12px 0; }
.art-feat .body p { font-size: 15px; color: var(--text); }

/* ── article reading view ── */
.reader { display: grid; grid-template-columns: 1fr 240px; gap: 56px; max-width: 1080px; margin: 0 auto; align-items: start; }
.prose { max-width: 720px; }
.prose > p { font-size: 17px; color: var(--text); margin: 20px 0; line-height: 1.75; }
.prose h2 { font-size: 27px; font-weight: 800; color: var(--text-hi); letter-spacing: -.6px; margin: 44px 0 16px; scroll-margin-top: 90px; }
.prose h3 { font-size: 20px; font-weight: 700; color: var(--text-hi); margin: 32px 0 12px; scroll-margin-top: 90px; }
.prose ul, .prose ol { margin: 18px 0 18px 22px; color: var(--text); }
.prose li { margin: 9px 0; font-size: 16px; }
.prose strong { color: var(--text-hi); font-weight: 600; }
.prose a { color: var(--cyan); text-decoration: underline; text-underline-offset: 2px; }
.callout { display: flex; gap: 14px; background: rgba(56,189,248,.06); border: 1px solid rgba(56,189,248,.22); border-left-width: 3px; border-radius: 12px; padding: 18px 20px; margin: 26px 0; }
.callout .ci { color: var(--cyan); flex-shrink: 0; }
.callout p { margin: 0 !important; font-size: 15px !important; color: var(--text) !important; }
.callout.warn { background: rgba(251,146,60,.06); border-color: rgba(251,146,60,.24); }
.callout.warn .ci { color: var(--orange); }
.code { background: #0B0E15; border: 1px solid var(--border); border-radius: 12px; margin: 24px 0; overflow: hidden; }
.code .cbar { display: flex; align-items: center; justify-content: space-between; padding: 10px 16px; border-bottom: 1px solid var(--border); }
.code .cbar .fn { font-family: var(--mono); font-size: 12px; color: var(--text-mid); }
.code .cbar .cp { font-family: var(--mono); font-size: 11px; color: var(--text-low); cursor: pointer; }
.code pre { padding: 18px 20px; overflow-x: auto; font-family: var(--mono); font-size: 13.5px; line-height: 1.7; color: #C9D3E0; }
.code .k { color: var(--purple); } .code .s { color: var(--emerald); } .code .c { color: var(--text-low); } .code .fn2 { color: var(--cyan); }
.diagram-inline { background: radial-gradient(120% 120% at 50% 0%, var(--surface-2), var(--bg-2)); border: 1px solid var(--border); border-radius: 14px; height: 220px; position: relative; margin: 28px 0; overflow: hidden; }
.diagram-inline::before { content: ""; position: absolute; inset: 0; background-image: radial-gradient(var(--border-hi) 1px, transparent 1px); background-size: 22px 22px; opacity: .4; }
.toc { position: sticky; top: 90px; }
.toc h5 { font-family: var(--mono); font-size: 11px; text-transform: uppercase; letter-spacing: .8px; color: var(--text-low); margin-bottom: 14px; }
.toc a { display: block; font-size: 13.5px; color: var(--text-mid); padding: 6px 0 6px 14px; border-left: 2px solid var(--border); transition: color .15s, border-color .15s; }
.toc a:hover, .toc a.active { color: var(--text-hi); border-color: var(--cyan); }
.art-hero { max-width: 720px; margin: 0 auto; text-align: left; }
.art-hero h1 { font-size: clamp(30px, 4.4vw, 46px); font-weight: 800; letter-spacing: -1.4px; color: var(--text-hi); line-height: 1.08; margin: 16px 0; }
.art-meta { display: flex; gap: 16px; align-items: center; font-family: var(--mono); font-size: 13px; color: var(--text-mid); margin-top: 18px; }
.art-meta .av { width: 34px; height: 34px; border-radius: 50%; background: linear-gradient(135deg, var(--cyan), var(--blue)); display: flex; align-items: center; justify-content: center; font-family: var(--mono); font-weight: 700; color: #04121f; font-size: 13px; }
@media (max-width: 900px) { .reader { grid-template-columns: 1fr; gap: 0; } .toc { display: none; } .art-feat { grid-template-columns: 1fr; } .art-feat .vis { min-height: 160px; border-right: none; border-bottom: 1px solid var(--border); } }

@media (max-width: 900px) {
  .kbd { display: none; }
  .nav-toggle { display: flex; }
  .nav-menu { display: none; }
  .nav-mobile { position: absolute; top: 66px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 2px; background: rgba(8,9,13,.98); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-bottom: 1px solid var(--border); padding: 12px 20px 20px; display: none; }
  .nav-mobile.open { display: flex; }
  .nav-mobile a { padding: 12px 14px; font-size: 15px; color: var(--text); border-radius: 9px; }
  .nav-mobile a:hover, .nav-mobile a.active { background: var(--surface); color: var(--text-hi); }
  .diagrams, .grid-3, .grid-2, .pricing { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
}
@media (max-width: 560px) {
  .form-row { flex-direction: column; }
  .foot-grid { grid-template-columns: 1fr; }
  section.blk { padding: 64px 0; }
}