/* ============================================================
   PROJECT 1600 — GLOBAL STYLES
   Brand: black stage, silver lockup, yellow/red/green system
   ============================================================ */

:root {
  --bg:        #0a0a0a;
  --stage:     #161616;
  --stage-2:   #1d1d1d;
  --line:      #2c2c2c;
  --line-soft: #232323;

  --silver:    #d6d6d6;
  --silver-dim:#8a8a8a;
  --ink:       #f4f4f4;
  --muted:     #9a9a9a;
  --faint:     #6a6a6a;

  --yellow:    #f5c518;   /* Text 1 claims  */
  --red:       #ff5347;   /* Text 2 attacks */
  --green:     #34d17e;   /* correct answer */

  --easy:   #34d17e;
  --medium: #f5c518;
  --hard:   #ff5347;

  --radius: 14px;
  --maxw: 1080px;

  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans:  "Space Grotesk", "Helvetica Neue", Arial, sans-serif;
  --mono:  "JetBrains Mono", "SF Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
  min-height: 100vh;
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(245,197,24,0.05), transparent 70%),
    repeating-linear-gradient(0deg, transparent, transparent 39px, rgba(255,255,255,0.012) 39px, rgba(255,255,255,0.012) 40px);
}

a { color: inherit; text-decoration: none; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

/* ---------------- HEADER / LOCKUP ---------------- */
.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
  background: rgba(10,10,10,0.86);
  backdrop-filter: blur(10px);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px;
}
.lockup {
  display: flex; align-items: center; gap: 0;
  font-family: var(--mono);
  font-weight: 700; letter-spacing: 0.14em;
  font-size: 15px;
}
.lockup .p1 { color: var(--silver); }
.lockup .bar {
  color: var(--faint); margin: 0 9px; font-weight: 400;
  transform: translateY(-1px);
}
.lockup .p2 {
  color: var(--ink);
  background: linear-gradient(180deg, #fff, var(--silver-dim));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.lockup .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--yellow); margin-left: 10px;
  box-shadow: 0 0 10px var(--yellow);
}

.nav { display: flex; gap: 26px; font-size: 14px; }
.nav a {
  color: var(--muted); padding: 4px 0;
  border-bottom: 1px solid transparent;
  transition: color .15s, border-color .15s;
}
.nav a:hover { color: var(--ink); }
.nav a.active { color: var(--ink); border-bottom-color: var(--yellow); }

/* ---------------- FOOTER ---------------- */
.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 90px; padding: 40px 0;
  color: var(--faint); font-size: 13px;
}
.site-footer .wrap {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
.site-footer .tag { font-family: var(--mono); letter-spacing: 0.06em; }

/* ---------------- TYPOGRAPHY HELPERS ---------------- */
.kicker {
  font-family: var(--mono); font-size: 12px;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--yellow);
}
.section-title {
  font-family: var(--serif); font-weight: 500;
  font-size: clamp(28px, 4vw, 44px); line-height: 1.1;
  letter-spacing: -0.01em;
}
.lead { color: var(--muted); font-size: 17px; max-width: 60ch; }

/* ---------------- BADGES ---------------- */
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--mono); font-size: 11px;
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 4px 9px; border-radius: 999px;
  border: 1px solid var(--line);
}
.badge::before {
  content: ""; width: 6px; height: 6px; border-radius: 50%;
  background: currentColor;
}
.badge.easy   { color: var(--easy); }
.badge.medium { color: var(--medium); }
.badge.hard   { color: var(--hard); }
.badge.rw     { color: var(--silver); }
.badge.math   { color: #6fb3ff; }

/* ---------------- BUTTONS ---------------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--sans); font-weight: 600; font-size: 14px;
  padding: 11px 20px; border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--stage-2); color: var(--ink);
  cursor: pointer; transition: transform .12s, border-color .15s, background .15s;
}
.btn:hover { transform: translateY(-2px); border-color: var(--silver-dim); }
.btn.primary {
  background: var(--yellow); color: #1a1500;
  border-color: var(--yellow); font-weight: 700;
}
.btn.primary:hover { box-shadow: 0 8px 28px rgba(245,197,24,0.25); }
.btn.ghost { background: transparent; }

/* ============================================================
   HERO (landing)
   ============================================================ */
.hero { padding: 86px 0 60px; position: relative; }
.hero .eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.16em;
  color: var(--muted); border: 1px solid var(--line);
  padding: 6px 12px; border-radius: 999px; margin-bottom: 28px;
}
.hero .eyebrow b { color: var(--yellow); font-weight: 700; }
.hero h1 {
  font-family: var(--serif); font-weight: 500;
  font-size: clamp(40px, 7vw, 84px); line-height: 1.02;
  letter-spacing: -0.02em; max-width: 16ch;
}
.hero h1 .hl {
  position: relative; color: var(--ink);
  background: linear-gradient(transparent 62%, rgba(245,197,24,0.32) 62%);
}
.hero p.lead { margin-top: 24px; font-size: 19px; }
.hero .cta-row { display: flex; gap: 14px; margin-top: 36px; flex-wrap: wrap; }

.stat-strip {
  display: flex; gap: 0; margin-top: 64px;
  border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden;
}
.stat-strip .stat {
  flex: 1; padding: 24px 26px;
  border-right: 1px solid var(--line-soft);
}
.stat-strip .stat:last-child { border-right: none; }
.stat-strip .num {
  font-family: var(--serif); font-size: 38px; color: var(--ink);
}
.stat-strip .lbl {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--faint); margin-top: 4px;
}

/* ---------------- COLOR LEGEND (brand explainer) ---------------- */
.legend {
  margin-top: 70px; padding: 30px;
  background: var(--stage); border: 1px solid var(--line);
  border-radius: var(--radius);
}
.legend h3 {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--faint); margin-bottom: 18px;
}
.legend-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px;
}
.legend-item { display: flex; gap: 12px; align-items: flex-start; }
.legend-swatch {
  width: 30px; height: 30px; border-radius: 7px; flex-shrink: 0;
  margin-top: 2px;
}
.legend-item .lt { font-weight: 600; font-size: 14px; }
.legend-item .ld { color: var(--muted); font-size: 13px; }

/* ============================================================
   SECTION CARDS (landing -> rw / math)
   ============================================================ */
.split {
  display: grid; grid-template-columns: 1fr 1fr; gap: 22px;
  margin-top: 30px;
}
.path-card {
  display: block; padding: 34px 32px;
  background: var(--stage); border: 1px solid var(--line);
  border-radius: var(--radius); position: relative;
  transition: transform .15s, border-color .15s;
  overflow: hidden;
}
.path-card:hover { transform: translateY(-4px); border-color: var(--silver-dim); }
.path-card::after {
  content: ""; position: absolute; right: -40px; bottom: -40px;
  width: 160px; height: 160px; border-radius: 50%;
  background: var(--accent, var(--yellow)); opacity: 0.06;
}
.path-card .pc-num {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
}
.path-card h3 {
  font-family: var(--serif); font-size: 30px; font-weight: 500;
  margin: 14px 0 10px;
}
.path-card p { color: var(--muted); font-size: 14px; }
.path-card .pc-meta {
  margin-top: 22px; display: flex; gap: 8px; flex-wrap: wrap;
}
.path-card .go {
  margin-top: 24px; font-family: var(--mono); font-size: 13px;
  color: var(--ink); display: flex; align-items: center; gap: 8px;
}
.path-card .go .arrow { transition: transform .15s; }
.path-card:hover .go .arrow { transform: translateX(5px); }

/* ============================================================
   QUESTION BANK LIST
   ============================================================ */
.bank-head { padding: 56px 0 26px; }
.bank-head h1 {
  font-family: var(--serif); font-weight: 500;
  font-size: clamp(34px, 5vw, 56px); letter-spacing: -0.015em;
}
.bank-head .crumbs {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
  margin-bottom: 16px; letter-spacing: 0.06em;
}
.bank-head .crumbs a:hover { color: var(--ink); }

.filters {
  display: flex; gap: 10px; flex-wrap: wrap;
  padding: 18px 0 8px; border-bottom: 1px solid var(--line);
}
.filter-group { display: flex; gap: 6px; }
.chip {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em;
  padding: 7px 13px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--stage);
  color: var(--muted); cursor: pointer;
  transition: all .13s;
}
.chip:hover { color: var(--ink); border-color: var(--silver-dim); }
.chip.active {
  color: #1a1500; background: var(--yellow); border-color: var(--yellow);
  font-weight: 700;
}
.filter-spacer { flex: 1; }
.result-count {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
  align-self: center;
}

.q-list { margin-top: 8px; }
.q-row {
  display: grid;
  grid-template-columns: 64px 1fr auto;
  gap: 20px; align-items: center;
  padding: 20px 22px;
  border-bottom: 1px solid var(--line-soft);
  cursor: pointer; transition: background .12s;
}
.q-row:hover { background: var(--stage); }
.q-row .q-id {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
}
.q-row .q-main .q-domain {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--silver-dim);
}
.q-row .q-main .q-title {
  font-size: 16px; color: var(--ink); margin-top: 3px;
}
.q-row .q-tags { display: flex; gap: 8px; align-items: center; }
.q-empty {
  padding: 60px 20px; text-align: center; color: var(--faint);
  font-family: var(--mono); font-size: 13px;
}

/* ============================================================
   QUESTION DETAIL PAGE
   ============================================================ */
.q-detail { padding: 48px 0 0; }
.q-detail .crumbs {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
  margin-bottom: 22px; letter-spacing: 0.06em;
}
.q-detail .crumbs a:hover { color: var(--ink); }

.q-header {
  display: flex; gap: 10px; flex-wrap: wrap; align-items: center;
  margin-bottom: 8px;
}
.q-header .q-code {
  font-family: var(--mono); font-size: 12px; color: var(--faint);
  margin-left: auto;
}
.q-detail h1 {
  font-family: var(--serif); font-weight: 500; font-size: 30px;
  letter-spacing: -0.01em; margin: 6px 0 28px;
}

/* the stage — mirrors the video widget */
.stage {
  background: var(--stage); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 32px 34px;
}
.stage .stim {
  font-family: var(--serif); font-size: 17px; line-height: 1.7;
  color: #e4e4e4; white-space: pre-wrap;
  border-left: 2px solid var(--line); padding-left: 18px;
  margin-bottom: 26px;
}
.stage .prompt {
  font-size: 16px; font-weight: 600; color: var(--ink);
  margin-bottom: 20px;
}

.choices { display: flex; flex-direction: column; gap: 10px; }
.choice {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 15px 18px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--stage-2);
  cursor: pointer; transition: all .14s;
  text-align: left; width: 100%; font-family: var(--sans);
  color: var(--ink); font-size: 15px; line-height: 1.5;
}
.choice:hover:not(.locked) { border-color: var(--silver-dim); transform: translateX(3px); }
.choice .ltr {
  font-family: var(--mono); font-weight: 700; font-size: 13px;
  width: 24px; height: 24px; border-radius: 6px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  background: #000; border: 1px solid var(--line); color: var(--silver);
}
.choice.locked { cursor: default; }
.choice.dim { opacity: 0.34; }
.choice.correct {
  border-color: var(--green);
  background: rgba(52,209,126,0.10);
  box-shadow: 0 0 0 1px var(--green) inset;
}
.choice.correct .ltr { background: var(--green); color: #00150a; border-color: var(--green); }
.choice.wrong-pick {
  border-color: var(--red);
  background: rgba(255,83,71,0.08);
}
.choice.wrong-pick .ltr { background: var(--red); color: #1a0200; border-color: var(--red); }

/* answer reveal / lesson card */
.reveal { margin-top: 22px; display: none; }
.reveal.show { display: block; animation: rise .4s ease both; }
@keyframes rise { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.verdict {
  font-family: var(--mono); font-size: 13px; letter-spacing: 0.06em;
  padding: 12px 16px; border-radius: 9px; margin-bottom: 14px;
}
.verdict.right { background: rgba(52,209,126,0.12); color: var(--green); }
.verdict.miss  { background: rgba(255,83,71,0.10); color: var(--red); }

.explain-block {
  border: 1px solid var(--line); border-radius: 11px;
  padding: 4px 20px; background: #000;
}
.explain-row { padding: 16px 0; border-bottom: 1px solid var(--line-soft); }
.explain-row:last-child { border-bottom: none; }
.explain-row .er-label {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em;
  text-transform: uppercase; margin-bottom: 7px;
  display: flex; align-items: center; gap: 7px;
}
.explain-row .er-label::before {
  content: ""; width: 7px; height: 7px; border-radius: 2px;
  background: currentColor;
}
.er-label.correct { color: var(--green); }
.er-label.trap    { color: var(--red); }
.er-label.lesson  { color: var(--yellow); }
.explain-row p { font-size: 14px; color: #d4d4d4; line-height: 1.65; }

.lesson-card {
  margin-top: 16px; padding: 20px 22px;
  background: linear-gradient(135deg, rgba(52,209,126,0.10), rgba(52,209,126,0.02));
  border: 1px solid rgba(52,209,126,0.35);
  border-radius: 11px;
}
.lesson-card .lc-tag {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--green); margin-bottom: 8px;
}
.lesson-card p { font-size: 15px; color: #e8e8e8; line-height: 1.6; }

/* prev / next nav */
.q-nav {
  display: flex; justify-content: space-between; gap: 14px;
  margin-top: 34px; padding-top: 22px;
}
.q-nav a {
  flex: 1; padding: 16px 18px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--stage);
  transition: border-color .15s, transform .12s;
}
.q-nav a:hover { border-color: var(--silver-dim); transform: translateY(-2px); }
.q-nav a.disabled { opacity: 0.32; pointer-events: none; }
.q-nav .dir {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em;
  color: var(--faint); text-transform: uppercase;
}
.q-nav .nt { font-size: 14px; color: var(--ink); margin-top: 4px; }
.q-nav a.next { text-align: right; }

/* ---------------- generic content pages (about / how) ---------------- */
.page { padding: 56px 0; }
.page h1 {
  font-family: var(--serif); font-weight: 500;
  font-size: clamp(34px, 5vw, 52px); letter-spacing: -0.015em;
  margin-bottom: 10px;
}
.page h2 {
  font-family: var(--serif); font-weight: 500; font-size: 24px;
  margin: 38px 0 12px;
}
.page p { color: var(--muted); font-size: 16px; margin-bottom: 14px; max-width: 68ch; }
.page p strong { color: var(--ink); }
.page ul { margin: 4px 0 16px 22px; color: var(--muted); }
.page li { margin-bottom: 8px; }
.step-list { counter-reset: step; list-style: none; margin-left: 0; }
.step-list li {
  position: relative; padding-left: 46px; margin-bottom: 18px;
  color: var(--muted);
}
.step-list li::before {
  counter-increment: step; content: counter(step);
  position: absolute; left: 0; top: -2px;
  width: 30px; height: 30px; border-radius: 8px;
  background: var(--stage-2); border: 1px solid var(--line);
  color: var(--yellow); font-family: var(--mono); font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

/* ---------------- responsive ---------------- */
@media (max-width: 760px) {
  .wrap { padding: 0 18px; }
  .nav { gap: 16px; font-size: 13px; }
  .split { grid-template-columns: 1fr; }
  .legend-grid { grid-template-columns: 1fr; }
  .stat-strip { flex-direction: column; }
  .stat-strip .stat { border-right: none; border-bottom: 1px solid var(--line-soft); }
  .q-row { grid-template-columns: 1fr; gap: 10px; }
  .q-row .q-id { order: -1; }
  .q-nav { flex-direction: column; }
  .stage { padding: 22px 18px; }
  .filter-spacer { display: none; }
  .result-count { width: 100%; }
}