/* ============================================================
   /learn/ — page-specific styles only.
   site.css loads first and supplies the tokens, type scale,
   buttons, header, mobile menu and footer. Nothing here
   redefines those; this file adds the trace, the gate panels,
   the artifacts, the SPF tool and the quiz.
   ============================================================ */

/* ---------- lead (dark, matches the homepage hero) ---------- */
.lead{
  background:radial-gradient(120% 90% at 82% 0%,#1B2C3C 0%,var(--ink) 62%);
  color:var(--paper);
  padding:76px 0 68px;
  position:relative;
}
.lead::after{
  content:"";position:absolute;inset:auto 0 0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(232,163,61,.5),transparent);
}
.lead .eyebrow{color:var(--amber)}
.lead h1{font-size:clamp(38px,5.4vw,58px);font-weight:800;letter-spacing:-.028em;margin-bottom:20px}
.lead .lede{font-size:19.5px;color:var(--ice);max-width:34em;margin:0}
.hero-rule{width:56px;height:3px;background:var(--amber);margin-bottom:26px}

/* ---------- the request trace ---------- */
.trace{background:rgba(11,19,27,.72);border:1px solid rgba(159,185,207,.24);border-radius:12px;padding:26px 24px 22px;margin-top:38px;box-shadow:0 26px 70px rgba(0,0,0,.45)}
.trace-head{display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:space-between;margin-bottom:30px}
.trace-title{font-family:var(--mono);font-size:11.5px;letter-spacing:.16em;text-transform:uppercase;color:var(--ice);margin:0}
.controls{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.controls .btn{padding:10px 18px;font-size:14px}

.toggle{display:inline-flex;align-items:center;gap:10px;font-family:var(--mono);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--ice);cursor:pointer;user-select:none}
.toggle input{position:absolute;opacity:0;width:1px;height:1px}
.switch{width:42px;height:22px;border-radius:16px;background:var(--signal);border:1px solid transparent;position:relative;transition:background .2s;flex:none}
.switch::after{content:"";position:absolute;top:2px;left:2px;width:16px;height:16px;border-radius:50%;background:var(--ink);transition:transform .2s}
.toggle input:not(:checked) + .switch{background:rgba(159,185,207,.18);border-color:rgba(159,185,207,.3)}
.toggle input:not(:checked) + .switch::after{transform:translateX(20px);background:var(--ember)}
.toggle input:focus-visible + .switch{outline:3px solid var(--amber);outline-offset:3px}

.track{position:relative;display:flex;justify-content:space-between;align-items:flex-start;gap:8px;padding-bottom:6px}
.track::before{content:"";position:absolute;left:6%;right:6%;top:18px;height:1px;background:rgba(159,185,207,.22)}
.gate{position:relative;z-index:1;flex:1 1 0;min-width:0;display:flex;flex-direction:column;align-items:center;gap:10px;background:none;border:0;padding:0;color:inherit;font:inherit;cursor:pointer;text-align:center}
.node{width:36px;height:36px;border-radius:50%;background:var(--ink);border:1px solid rgba(159,185,207,.3);display:grid;place-items:center;font-family:var(--mono);font-size:12px;color:var(--ice);transition:border-color .25s,background .25s,color .25s,box-shadow .25s;flex:none}
.gate-name{font-family:var(--mono);font-size:10.5px;letter-spacing:.13em;text-transform:uppercase;color:var(--ice);transition:color .25s;line-height:1.3}
.gate.lit .node{border-color:var(--signal);color:var(--signal);box-shadow:0 0 0 4px rgba(95,168,138,.16)}
.gate.lit .gate-name{color:var(--paper)}
.gate.failed .node{border-color:var(--ember);color:var(--ember);background:rgba(196,100,58,.16);box-shadow:0 0 0 4px rgba(196,100,58,.16)}
.gate.failed .gate-name{color:var(--ember)}
.gate:hover .gate-name{color:var(--paper)}

.pulse{position:absolute;top:18px;left:0;width:10px;height:10px;border-radius:50%;background:var(--amber);margin:-5px 0 0 -5px;opacity:0;pointer-events:none;z-index:2;box-shadow:0 0 12px 2px rgba(232,163,61,.55)}
.pulse.on{opacity:1}
.pulse.bad{background:var(--ember);box-shadow:0 0 14px 3px rgba(196,100,58,.6)}

.readout{margin-top:24px;border-top:1px solid rgba(159,185,207,.2);padding-top:18px;font-family:var(--mono);font-size:12.5px;line-height:1.75;color:var(--ice);min-height:96px}
.readout p{margin:0 0 4px}
.readout .ok{color:var(--signal)}
.readout .bad{color:var(--ember)}
.readout .note{color:var(--paper);margin-top:12px;font-family:var(--serif);font-size:15.5px;line-height:1.6}

/* mobile: the track runs vertically */
@media(max-width:760px){
  .track{flex-direction:column;align-items:stretch;gap:16px;padding-left:2px}
  .track::before{left:18px;right:auto;top:14px;bottom:14px;height:auto;width:1px}
  .gate{flex-direction:row;align-items:center;gap:14px;text-align:left}
  .pulse{top:0;left:18px}
}

/* ---------- gate sections: same light/white rhythm as the homepage ---------- */
main > .section:nth-of-type(even){background:var(--white);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section-head{display:flex;gap:20px;align-items:baseline;margin-bottom:28px}
.marker{font-family:var(--mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;color:var(--amber);flex:none;padding-top:6px}
.what{color:var(--body-ink);max-width:60ch;margin:0 0 34px;font-size:17.5px}
.what strong{font-family:var(--display);font-weight:600;color:var(--midnight)}
@media(max-width:640px){.section-head{flex-direction:column;gap:6px}.marker{padding-top:0}}

/* ---------- open vs warded ---------- */
.compare{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.pane{background:var(--white);border:1px solid var(--line);border-radius:14px;padding:28px 26px}
main > .section:nth-of-type(even) .pane{background:var(--paper)}
.pane h3{display:flex;align-items:center;gap:10px;font-size:17px;margin-bottom:14px}
.pane h3::before{content:"";width:8px;height:8px;border-radius:50%;flex:none}
.pane-open h3{color:#A34A2E}
.pane-open h3::before{background:var(--ember)}
.pane-warded h3{color:#2F6B52}
.pane-warded h3::before{background:var(--signal)}
.pane ul{margin:0;padding-left:18px}
.pane li{margin-bottom:11px;font-size:15.5px;color:var(--body-ink);line-height:1.58}
.pane li:last-child{margin-bottom:0}
.pane strong{font-family:var(--display);font-weight:600;color:var(--midnight)}
@media(max-width:760px){.compare{grid-template-columns:1fr}}

/* ---------- terminal artifacts ---------- */
.artifact{margin-top:26px;background:var(--ink);border:1px solid var(--midnight);border-radius:12px;overflow:hidden}
.artifact-bar{font-family:var(--mono);font-size:10.5px;letter-spacing:.15em;text-transform:uppercase;color:var(--ice);padding:11px 16px;border-bottom:1px solid rgba(159,185,207,.18);background:rgba(159,185,207,.06)}
.artifact pre{margin:0;padding:18px 16px;overflow-x:auto;font-family:var(--mono);font-size:12.5px;line-height:1.8;color:var(--ice)}
.artifact .hl{color:var(--signal)}
.artifact .warn{color:var(--amber)}
.artifact .err{color:var(--ember)}
.artifact .cmd{color:#8FB4D4}

/* ---------- SPF tool ---------- */
.tool{background:var(--white);border:1px solid var(--line);border-radius:14px;padding:28px 26px;margin-top:26px}
main > .section:nth-of-type(even) .tool{background:var(--paper)}
.tool label{display:block;font-family:var(--mono);font-size:11.5px;letter-spacing:.13em;text-transform:uppercase;color:var(--steel);margin-bottom:10px}
.tool textarea{width:100%;min-height:92px;resize:vertical;background:var(--ink);color:var(--paper);border:1px solid var(--midnight);border-radius:9px;padding:14px;font-family:var(--mono);font-size:13px;line-height:1.65}
.tool textarea:focus{outline:3px solid var(--amber);outline-offset:2px}
.tool-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:16px}
.tool-actions .btn{padding:11px 20px;font-size:14px}
.tool-actions .ghost-dark{color:var(--steel);border-color:var(--line)}
.tool-actions .ghost-dark:hover{border-color:var(--steel);background:rgba(62,92,118,.06)}

.meter{margin-top:26px;display:none}
.meter.show{display:block}
.meter-top{display:flex;justify-content:space-between;align-items:baseline;font-family:var(--mono);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--steel);margin-bottom:8px}
.meter-count{font-family:var(--display);font-weight:800;font-size:42px;letter-spacing:-.03em;line-height:1;color:var(--midnight)}
.bar{height:8px;background:var(--line);border-radius:4px;overflow:hidden;margin-top:10px}
.bar span{display:block;height:100%;width:0;background:var(--signal);transition:width .5s ease,background .3s}
.bar.over span{background:var(--ember)}
.verdict{margin-top:16px;font-size:15.5px;color:var(--body-ink);line-height:1.6}
.verdict.over{color:#A34A2E}
.breakdown{margin-top:16px;font-family:var(--mono);font-size:12.5px;color:var(--steel);line-height:2}
.breakdown div{display:flex;justify-content:space-between;gap:16px;border-bottom:1px dotted var(--line);padding-bottom:2px}

/* ---------- quiz ---------- */
.quiz{background:var(--white);border:1px solid var(--line);border-radius:14px;padding:30px 28px}
main > .section:nth-of-type(even) .quiz{background:var(--paper)}
.q{margin-bottom:34px}
.q:last-of-type{margin-bottom:0}
.q > p{margin:0 0 14px;font-family:var(--display);font-weight:600;font-size:17.5px;line-height:1.4}
.opts{display:flex;flex-direction:column;gap:9px}
.opt{text-align:left;background:var(--paper);border:1px solid var(--line);color:var(--body-ink);border-radius:9px;padding:13px 16px;font:inherit;font-size:15.5px;cursor:pointer;transition:border-color .15s,color .15s,background .15s}
main > .section:nth-of-type(even) .opt{background:var(--white)}
.opt:hover{border-color:var(--steel);color:var(--midnight)}
.opt.right{border-color:var(--signal);color:#2F6B52;background:rgba(95,168,138,.1)}
.opt.wrong{border-color:var(--ember);color:#A34A2E;background:rgba(196,100,58,.09)}
.why{margin-top:14px;font-size:15.5px;color:var(--body-ink);border-left:3px solid var(--signal);padding-left:16px;display:none;line-height:1.6}
.why.miss{border-left-color:var(--ember)}
.why.show{display:block}

/* ---------- closing ---------- */
.cta{background:radial-gradient(120% 90% at 50% 0%,#1B2C3C 0%,var(--ink) 60%);color:var(--paper);text-align:center}
.cta .eyebrow{color:var(--amber)}
.cta h2{margin-bottom:18px}
.cta > .wrap > p{color:var(--ice);max-width:50ch;margin:0 auto 32px}
.btn-lg{font-size:16px;padding:15px 30px}