/* ============================================================
   VECTOR — Enhanced ACT Math. Design v2.
   Near-black, acid lime, Clash Display. Editorial / Higgsfield.
   ============================================================ */
:root {
  --bg: #060606;
  --panel: #0c0c0b;
  --panel-2: #111110;
  --line: rgba(255, 255, 255, 0.1);
  --line-2: rgba(255, 255, 255, 0.2);
  --text: #f4f4ef;
  --dim: #8f8f88;
  --faint: #55554f;
  --acc: #c8ff00;
  --acc-dim: rgba(200, 255, 0, 0.14);
  --hot: #ff4d00;
  --hot-dim: rgba(255, 77, 0, 0.12);
  --good: #c8ff00;
  --bad: #ff5c5c;
  --amber: #ffc24d;
  --r: 18px;
  --r-sm: 12px;
  --display: "Clash Display", "Space Grotesk", sans-serif;
  --body: "Satoshi", "Inter", sans-serif;
  --mono: "JetBrains Mono", monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
::selection { background: var(--acc); color: #000; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* film grain */
.noise {
  position: fixed; inset: -50%; z-index: 2000; pointer-events: none; opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='240' height='240' filter='url(%23n)' opacity='0.6'/%3E%3C/svg%3E");
  animation: grain 9s steps(10) infinite;
}
@keyframes grain {
  0%,100% { transform: translate(0,0); } 20% { transform: translate(-3%,2%); }
  40% { transform: translate(2%,-3%); } 60% { transform: translate(-2%,-2%); } 80% { transform: translate(3%,3%); }
}

/* ---------------- top bar ---------------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 18px;
  padding: 0 28px; height: 68px;
  position: sticky; top: 0; z-index: 100;
  background: rgba(6, 6, 6, 0.82); backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 11px; cursor: pointer; user-select: none; }
.brand-box {
  width: 30px; height: 30px; border-radius: 8px; background: var(--acc); color: #000;
  font-family: var(--mono); font-weight: 700; font-size: 17px;
  display: flex; align-items: center; justify-content: center;
}
.brand-name { font-family: var(--display); font-weight: 600; font-size: 17px; letter-spacing: 0.34em; }
.subject-switch { display: flex; gap: 2px; border: 1px solid var(--line); border-radius: 100px; padding: 3px; }
.subj {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.12em; font-weight: 500;
  background: transparent; color: var(--dim); border: none; border-radius: 100px;
  padding: 7px 14px; cursor: pointer; transition: all .2s;
}
.subj.active { background: var(--text); color: #000; font-weight: 700; }
.subj.soon { cursor: default; }
.subj.soon i { font-style: normal; font-size: 8px; color: var(--faint); vertical-align: super; margin-left: 2px; }
.topnav { display: flex; align-items: center; gap: 4px; }
.nav-btn {
  background: none; border: none; color: var(--dim); font-family: var(--body);
  font-size: 14px; font-weight: 500; padding: 9px 14px; border-radius: 100px;
  cursor: pointer; transition: color .2s;
}
.nav-btn:hover { color: var(--text); }
.nav-btn.active { color: var(--acc); }
.nav-cta {
  font-family: var(--mono); font-size: 12px; font-weight: 700; letter-spacing: 0.08em;
  background: var(--acc); color: #000; border: 1px solid var(--acc);
  padding: 10px 20px; border-radius: 100px; cursor: pointer; margin-left: 10px;
  transition: all .2s;
}
.nav-cta:hover { background: transparent; color: var(--acc); }

/* ---------------- layout ---------------- */
#app { max-width: 1240px; margin: 0 auto; padding: 0 28px 110px; min-height: 72vh; }
.section-tag {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em; color: var(--acc);
  text-transform: uppercase; display: flex; align-items: center; gap: 12px; margin-bottom: 18px;
}
.section-tag::after { content: ""; height: 1px; flex: 1; background: var(--line); }
.h-display {
  font-family: var(--display); font-weight: 600; letter-spacing: -0.02em; line-height: 1.02;
  text-transform: uppercase;
}

/* ---------------- hero ---------------- */
.hero { padding: 84px 0 56px; }
.hero-kicker {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.22em; color: var(--dim);
  text-transform: uppercase; margin-bottom: 26px; display: flex; align-items: center; gap: 10px;
}
.hero-kicker b { color: var(--acc); font-weight: 500; }
.hero-kicker .live-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--acc); box-shadow: 0 0 10px var(--acc); animation: pulse 2.2s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .25; } }
.hero h1 {
  font-family: var(--display); font-weight: 600; text-transform: uppercase;
  font-size: clamp(54px, 9.2vw, 124px); line-height: 0.94; letter-spacing: -0.025em;
  margin-bottom: 34px;
}
.hero h1 .outline {
  color: transparent; -webkit-text-stroke: 1.5px var(--text);
}
.hero h1 .lime { color: var(--acc); }
.hero-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.hero-sub { max-width: 480px; color: var(--dim); font-size: 16.5px; }
.hero-sub strong { color: var(--text); font-weight: 700; }
.hero-ctas { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------------- buttons ---------------- */
.btn {
  font-family: var(--mono); font-weight: 700; font-size: 12.5px; letter-spacing: 0.1em;
  text-transform: uppercase; padding: 17px 30px; border-radius: 100px; cursor: pointer;
  transition: all .22s; border: 1px solid transparent;
}
.btn:active { transform: scale(.97); }
.btn-acc { background: var(--acc); color: #000; border-color: var(--acc); }
.btn-acc:hover { background: transparent; color: var(--acc); box-shadow: 0 0 34px rgba(200,255,0,.18); }
.btn-hot { background: var(--hot); color: #fff; border-color: var(--hot); }
.btn-hot:hover { background: transparent; color: var(--hot); }
.btn-line { background: transparent; color: var(--text); border-color: var(--line-2); }
.btn-line:hover { border-color: var(--text); }
.btn-sm { padding: 11px 20px; font-size: 11px; }
.btn:disabled { opacity: .35; cursor: not-allowed; }

/* ---------------- marquee ---------------- */
.marquee {
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  overflow: hidden; white-space: nowrap; padding: 13px 0; margin: 52px -28px 0;
  user-select: none;
}
.marquee-track { display: inline-block; animation: scroll 30s linear infinite; }
.marquee span {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.2em; color: var(--dim);
  text-transform: uppercase; margin-right: 16px;
}
.marquee b { color: var(--acc); font-weight: 400; margin-right: 16px; }
@keyframes scroll { from { transform: translateX(0); } to { transform: translateX(-50%); } }

/* ---------------- bento modes ---------------- */
.bento { display: grid; grid-template-columns: repeat(6, 1fr); gap: 14px; margin-top: 8px; }
.tile {
  position: relative; overflow: hidden;
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--r);
  padding: 28px; cursor: pointer; transition: border-color .25s, transform .25s, background .25s;
  display: flex; flex-direction: column; min-height: 210px;
}
.tile:hover { border-color: rgba(200,255,0,.5); transform: translateY(-3px); background: var(--panel-2); }
.tile .t-num { font-family: var(--mono); font-size: 11px; color: var(--faint); letter-spacing: .14em; }
.tile h3 { font-family: var(--display); font-weight: 600; font-size: 25px; text-transform: uppercase; letter-spacing: -0.01em; margin: 12px 0 8px; }
.tile p { font-size: 14px; color: var(--dim); flex: 1; }
.tile .t-go {
  font-family: var(--mono); font-size: 12px; letter-spacing: .1em; color: var(--acc);
  margin-top: 18px; display: inline-flex; gap: 8px; align-items: center; transition: gap .25s;
}
.tile:hover .t-go { gap: 16px; }
.tile-l { grid-column: span 3; }
.tile-m { grid-column: span 2; }
.tile-s { grid-column: span 2; }
.tile-hot:hover { border-color: rgba(255,77,0,.55); }
.tile-hot .t-go { color: var(--hot); }
.tile .t-bignum {
  position: absolute; right: 18px; bottom: -26px; font-family: var(--display); font-weight: 700;
  font-size: 130px; line-height: 1; color: transparent; -webkit-text-stroke: 1px rgba(255,255,255,0.07);
  pointer-events: none;
}

/* ---------------- feature strip ---------------- */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; }
.feat { background: var(--bg); padding: 26px 26px 30px; }
.feat .f-ic { font-size: 19px; color: var(--acc); font-family: var(--mono); margin-bottom: 14px; display: block; }
.feat h4 { font-family: var(--display); font-size: 16.5px; font-weight: 600; text-transform: uppercase; letter-spacing: .02em; margin-bottom: 7px; }
.feat p { font-size: 13.5px; color: var(--dim); }

/* ---------------- generic panel ---------------- */
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 36px; }
.panel h2 { font-family: var(--display); font-size: 32px; font-weight: 600; text-transform: uppercase; letter-spacing: -0.01em; margin-bottom: 8px; }
.panel .desc { color: var(--dim); margin-bottom: 26px; font-size: 15px; max-width: 640px; }
.field-label { display: block; font-family: var(--mono); font-size: 10.5px; font-weight: 500; text-transform: uppercase; letter-spacing: 0.2em; color: var(--dim); margin: 28px 0 12px; }
.chip-row { display: flex; flex-wrap: wrap; gap: 9px; }
.chip {
  background: transparent; border: 1px solid var(--line-2); color: var(--dim);
  font-family: var(--body); font-size: 13.5px; font-weight: 500;
  padding: 10px 19px; border-radius: 100px; cursor: pointer; transition: all .18s;
}
.chip:hover { color: var(--text); border-color: var(--text); }
.chip.selected { background: var(--acc); border-color: var(--acc); color: #000; font-weight: 700; }
.chip.selected.hot { background: var(--hot); border-color: var(--hot); color: #fff; }

/* ---------------- quiz ---------------- */
.quiz-head { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin: 34px 0 18px; flex-wrap: wrap; }
.quiz-meta { display: flex; align-items: center; gap: 9px; flex-wrap: wrap; }
.pill {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.12em; text-transform: uppercase;
  padding: 7px 14px; border-radius: 100px; border: 1px solid var(--line-2); color: var(--dim);
}
.pill.diff-1, .pill.diff-2 { color: var(--acc); border-color: rgba(200,255,0,.4); }
.pill.diff-3 { color: var(--amber); border-color: rgba(255,194,77,.4); }
.pill.diff-4, .pill.diff-5 { color: var(--hot); border-color: rgba(255,77,0,.5); }
.pill.smart { color: #000; background: var(--acc); border-color: var(--acc); font-weight: 700; }
.timer {
  font-family: var(--mono); font-size: 22px; font-weight: 500;
  padding: 8px 18px; border-radius: var(--r-sm); border: 1px solid var(--line-2);
}
.timer.low { color: var(--hot); border-color: var(--hot); animation: pulse 1s infinite; }

.q-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 38px; }
.q-number { font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase; color: var(--acc); margin-bottom: 16px; }
.q-text { font-size: 19px; line-height: 1.7; margin-bottom: 16px; max-width: 720px; }
.q-text .katex { font-size: 1.07em; }

/* figures */
.q-fig { margin: 6px 0 24px; }
.q-fig svg { max-width: 380px; width: 100%; height: auto; display: block; background: #0a0a09; border: 1px solid var(--line); border-radius: var(--r-sm); }
.q-table { border-collapse: collapse; margin: 4px 0 10px; font-size: 15px; background: #0a0a09; border-radius: var(--r-sm); overflow: hidden; }
.q-table th, .q-table td { border: 1px solid var(--line-2); padding: 9px 18px; text-align: center; font-family: var(--mono); font-size: 13.5px; }
.q-table th { color: var(--acc); background: rgba(200,255,0,0.05); font-weight: 500; }
.q-table td { color: var(--text); }

.choices { display: grid; gap: 10px; max-width: 720px; }
.choice {
  display: flex; align-items: center; gap: 16px; text-align: left;
  background: transparent; border: 1px solid var(--line-2); border-radius: var(--r-sm);
  padding: 15px 18px; cursor: pointer; transition: all .15s;
  font-family: var(--body); font-size: 16px; color: var(--text); width: 100%;
}
.choice:hover { border-color: var(--acc); background: var(--acc-dim); }
.choice-letter {
  flex-shrink: 0; width: 34px; height: 34px; border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-weight: 700; font-size: 13.5px;
  border: 1px solid var(--line-2); color: var(--dim); transition: all .15s;
}
.choice.selected { border-color: var(--acc); background: var(--acc-dim); }
.choice.selected .choice-letter { background: var(--acc); color: #000; border-color: var(--acc); }
.choice.correct { border-color: var(--acc); background: var(--acc-dim); }
.choice.correct .choice-letter { background: var(--acc); color: #000; border-color: var(--acc); }
.choice.wrong { border-color: var(--bad); background: rgba(255,92,92,.08); }
.choice.wrong .choice-letter { background: var(--bad); color: #000; border-color: var(--bad); }
.choice:disabled { cursor: default; }
.choice:disabled:hover { background: transparent; border-color: var(--line-2); }
.choice.correct:disabled:hover { border-color: var(--acc); background: var(--acc-dim); }
.choice.wrong:disabled:hover { border-color: var(--bad); background: rgba(255,92,92,.08); }

.explain { margin-top: 24px; padding: 20px 24px; border-radius: var(--r-sm); border: 1px solid rgba(200,255,0,.35); background: rgba(200,255,0,.04); font-size: 15px; max-width: 720px; }
.explain .ex-title { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--acc); margin-bottom: 8px; }
.explain.wrong-box { border-color: rgba(255,92,92,.4); background: rgba(255,92,92,.05); }
.explain.wrong-box .ex-title { color: var(--bad); }

.quiz-actions { display: flex; justify-content: space-between; align-items: center; margin-top: 26px; gap: 12px; flex-wrap: wrap; }
.kbd-hint { color: var(--faint); font-size: 12px; font-family: var(--mono); }
.kbd-hint kbd { border: 1px solid var(--line-2); border-radius: 5px; padding: 1px 6px; font-size: 10.5px; }

/* ---------------- test navigator ---------------- */
.test-layout { display: grid; grid-template-columns: 1fr 230px; gap: 18px; align-items: start; }
.navigator { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; position: sticky; top: 86px; }
.navigator h4 { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--dim); margin-bottom: 13px; }
.nav-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
.nav-cell {
  aspect-ratio: 1; border-radius: 7px; border: 1px solid var(--line);
  background: transparent; color: var(--faint); font-family: var(--mono); font-size: 11.5px;
  cursor: pointer; transition: all .12s; display: flex; align-items: center; justify-content: center;
}
.nav-cell:hover { border-color: var(--text); color: var(--text); }
.nav-cell.answered { background: var(--acc-dim); border-color: rgba(200,255,0,.45); color: var(--acc); }
.nav-cell.flagged { box-shadow: inset 0 0 0 2px var(--amber); }
.nav-cell.current { border-color: var(--text); color: var(--text); background: rgba(255,255,255,.07); }
.nav-legend { margin-top: 14px; font-size: 11px; color: var(--faint); display: grid; gap: 5px; font-family: var(--mono); }
.nav-legend span { display: flex; align-items: center; gap: 8px; }
.dot { width: 9px; height: 9px; border-radius: 3px; display: inline-block; }
.dot.d-ans { background: var(--acc-dim); border: 1px solid rgba(200,255,0,.45); }
.dot.d-flag { border: 2px solid var(--amber); }
.dot.d-cur { border: 1px solid var(--text); background: rgba(255,255,255,.07); }
.flag-btn { background: none; border: 1px solid var(--line-2); color: var(--dim); padding: 8px 15px; border-radius: 100px; cursor: pointer; font-size: 12px; font-family: var(--mono); letter-spacing: .06em; transition: all .2s; }
.flag-btn:hover, .flag-btn.on { border-color: var(--amber); color: var(--amber); }

/* ---------------- results ---------------- */
.score-hero { text-align: center; padding: 64px 20px 40px; }
.score-giant {
  font-family: var(--display); font-weight: 700; font-size: clamp(110px, 19vw, 230px);
  line-height: .9; color: var(--acc); letter-spacing: -0.04em;
}
.score-of { font-family: var(--mono); font-size: 12px; letter-spacing: .3em; color: var(--dim); text-transform: uppercase; margin-top: 14px; }
.score-sub { color: var(--dim); font-size: 15.5px; margin: 22px 0 30px; }
.score-sub strong { color: var(--text); }

.topic-bars { display: grid; gap: 13px; margin-top: 6px; }
.tbar { display: grid; grid-template-columns: 200px 1fr 64px; align-items: center; gap: 16px; font-size: 13.5px; }
.tbar .tname { color: var(--dim); text-align: right; font-family: var(--mono); font-size: 12px; }
.tbar .track { height: 8px; border-radius: 100px; background: rgba(255,255,255,.06); overflow: hidden; }
.tbar .fill { height: 100%; border-radius: 100px; background: var(--acc); transition: width .9s cubic-bezier(.2,.8,.2,1); }
.tbar .fill.low { background: var(--hot); }
.tbar .tpct { font-family: var(--mono); font-size: 12.5px; color: var(--dim); }

.review-list { display: grid; gap: 12px; margin-top: 26px; }
.review-item { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r-sm); padding: 22px 26px; }
.review-item.was-wrong { border-left: 3px solid var(--bad); }
.review-item.was-right { border-left: 3px solid var(--acc); }
.review-item.was-skip { border-left: 3px solid var(--faint); }
.review-q { font-size: 15.5px; margin-bottom: 10px; }
.review-meta { font-family: var(--mono); font-size: 11.5px; color: var(--dim); margin-bottom: 10px; display: flex; gap: 16px; flex-wrap: wrap; letter-spacing: .04em; }
.review-meta .rm-good { color: var(--acc); }
.review-meta .rm-bad { color: var(--bad); }
.review-ex { font-size: 14px; color: var(--dim); border-top: 1px dashed var(--line); padding-top: 12px; margin-top: 6px; }

/* ---------------- stats ---------------- */
.stat-strip { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; margin: 26px 0; }
.stat-card { background: var(--bg); padding: 26px; }
.stat-card .num { font-family: var(--mono); font-size: 38px; font-weight: 700; line-height: 1; color: var(--acc); margin-bottom: 8px; }
.stat-card .lbl { font-family: var(--mono); font-size: 10px; color: var(--dim); text-transform: uppercase; letter-spacing: 0.18em; }
.insight {
  display: flex; gap: 14px; align-items: flex-start;
  border: 1px solid rgba(200,255,0,.3); background: rgba(200,255,0,.04);
  border-radius: var(--r-sm); padding: 18px 22px; margin: 18px 0; font-size: 14.5px;
}
.insight .i-ic { font-family: var(--mono); color: var(--acc); font-size: 16px; }
.insight b { color: var(--text); }
.insight.warn { border-color: rgba(255,77,0,.35); background: var(--hot-dim); }
.insight.warn .i-ic { color: var(--hot); }

/* ---------------- courses ---------------- */
.course-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 10px; }
.course {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--r);
  padding: 30px; display: flex; flex-direction: column; transition: all .25s; position: relative; overflow: hidden;
}
.course:hover { border-color: rgba(200,255,0,.45); transform: translateY(-3px); }
.course.flagship { border-color: rgba(200,255,0,.5); background: linear-gradient(180deg, rgba(200,255,0,.05), transparent 50%), var(--panel); }
.course .c-tag { font-family: var(--mono); font-size: 10px; letter-spacing: .2em; color: var(--acc); text-transform: uppercase; margin-bottom: 16px; }
.course h3 { font-family: var(--display); font-size: 30px; font-weight: 600; text-transform: uppercase; line-height: 1; }
.course .c-score { font-family: var(--display); font-weight: 700; font-size: 76px; line-height: 1; color: var(--acc); margin: 18px 0 4px; }
.course .c-score small { font-size: 22px; color: var(--dim); font-weight: 500; }
.course ul { list-style: none; margin: 18px 0 24px; flex: 1; display: grid; gap: 9px; }
.course li { font-size: 13.5px; color: var(--dim); padding-left: 20px; position: relative; }
.course li::before { content: "→"; position: absolute; left: 0; color: var(--acc); font-family: var(--mono); font-size: 12px; }
.course .c-price { font-family: var(--mono); font-size: 13px; color: var(--dim); margin-bottom: 14px; }
.course .c-price b { color: var(--text); font-size: 17px; }

/* ---------------- footer ---------------- */
.footer { border-top: 1px solid var(--line); overflow: hidden; }
.footer-marquee {
  font-family: var(--display); font-weight: 700; text-transform: uppercase;
  font-size: clamp(90px, 17vw, 210px); line-height: 1; white-space: nowrap;
  color: transparent; -webkit-text-stroke: 1px rgba(255,255,255,.1);
  letter-spacing: .06em; padding: 18px 0 4px; user-select: none;
  display: flex; animation: scroll 24s linear infinite; width: max-content;
}
.footer-fine { font-size: 11.5px; color: var(--faint); max-width: 740px; margin: 0 auto; padding: 22px 24px 46px; text-align: center; }

/* ---------------- misc ---------------- */
.center { text-align: center; }
.mt-30 { margin-top: 30px; }
.row-between { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 14px; }
.empty-note { text-align: center; color: var(--faint); padding: 50px 0; font-size: 14px; font-family: var(--mono); }
.streak-fire { color: var(--amber); font-weight: 700; }
.test-info-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--r-sm); overflow: hidden; margin: 24px 0; }
.tig { background: var(--bg); padding: 20px; text-align: center; }
.tig .v { font-family: var(--mono); font-size: 27px; font-weight: 700; color: var(--acc); }
.tig .k { font-family: var(--mono); font-size: 9.5px; color: var(--dim); text-transform: uppercase; letter-spacing: .16em; margin-top: 6px; }
.section-block { margin-top: 84px; }

.reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------------- responsive ---------------- */
@media (max-width: 980px) {
  .bento { grid-template-columns: repeat(2, 1fr); }
  .tile-l, .tile-m, .tile-s { grid-column: span 2; }
  .feat-grid { grid-template-columns: 1fr; }
  .course-grid { grid-template-columns: 1fr; }
  .subject-switch { display: none; }
}
@media (max-width: 760px) {
  .topbar { padding: 0 14px; height: 60px; }
  .topnav .nav-btn { padding: 8px 8px; font-size: 13px; }
  #app { padding: 0 16px 80px; }
  .hero { padding: 52px 0 40px; }
  .stat-strip { grid-template-columns: repeat(2, 1fr); }
  .test-layout { grid-template-columns: 1fr; }
  .navigator { position: static; order: -1; }
  .nav-grid { grid-template-columns: repeat(9, 1fr); }
  .q-card { padding: 24px 18px; }
  .tbar { grid-template-columns: 110px 1fr 50px; }
  .test-info-grid { grid-template-columns: repeat(2, 1fr); }
  .marquee { margin: 40px -16px 0; }
}

/* ============================================================
   V3 — INTERACTIVE LAYER
   spotlight tiles, 3D tilt, magnetic CTAs, view transitions,
   hero figure, pro courses, count-up score
   ============================================================ */

/* ---- view transitions ---- */
#app.view-enter > * { animation: viewIn .45s cubic-bezier(.2,.8,.2,1) both; }
@keyframes viewIn { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

/* ---- custom scrollbar / focus ---- */
::-webkit-scrollbar { width: 11px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #1d1d1b; border-radius: 100px; border: 3px solid var(--bg); }
::-webkit-scrollbar-thumb:hover { background: #2c2c29; }
:focus-visible { outline: 2px solid var(--acc); outline-offset: 3px; border-radius: 4px; }

/* ---- hero: the function field ---- */
.hero { position: relative; min-height: min(640px, 82vh); display: flex; flex-direction: column; justify-content: center; }
.hero-canvas {
  position: absolute; top: 0; left: 50%; transform: translateX(-50%);
  z-index: 0; pointer-events: none;
}
.hero > :not(.hero-canvas):not(.eq-chip) { position: relative; z-index: 1; }
.hero .eq-chip {
  position: absolute; top: 0; right: 0; z-index: 1;
  display: flex; flex-direction: column; gap: 5px; align-items: flex-end;
  pointer-events: none; text-align: right;
}
.eq-fx {
  font-family: var(--mono); font-size: 11.5px; font-weight: 400;
  color: rgba(244, 244, 239, 0.55); letter-spacing: 0.04em;
}
.eq-fx.typing::after { content: "▌"; animation: pulse 0.8s infinite; }
.eq-hint { font-family: var(--mono); font-size: 8.5px; letter-spacing: .16em; color: rgba(244, 244, 239, 0.22); }
@media (max-width: 1100px) { .hero .eq-chip { display: none; } }
@media (min-width: 1101px) { .hero-kicker { max-width: calc(100% - 330px); } }

/* ---- clickable insight ---- */
.insight.clickable { cursor: pointer; transition: border-color .2s, transform .2s; }
.insight.clickable:hover { border-color: var(--hot); transform: translateX(3px); }

/* ---- spotlight + tilt tiles ---- */
.tile { transform-style: preserve-3d; will-change: transform; }
.tile::before {
  content: ""; position: absolute; inset: 0; opacity: 0; transition: opacity .3s; pointer-events: none;
  background: radial-gradient(440px circle at var(--mx, 50%) var(--my, 0%), rgba(200,255,0,.09), transparent 65%);
}
.tile:hover::before { opacity: 1; }
.tile-hot::before { background: radial-gradient(440px circle at var(--mx, 50%) var(--my, 0%), rgba(255,77,0,.1), transparent 65%); }

/* ---- magnetic CTA ---- */
.magnet { transition: transform .18s cubic-bezier(.2,.8,.2,1), background .22s, color .22s, box-shadow .22s; will-change: transform; }

/* ---- nav underline ---- */
.nav-btn { position: relative; }
.nav-btn::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 4px; height: 1.5px;
  background: var(--acc); transform: scaleX(0); transform-origin: left; transition: transform .25s;
}
.nav-btn:hover::after, .nav-btn.active::after { transform: scaleX(1); }

/* ---- question card accent ---- */
.q-card { position: relative; overflow: hidden; }
.q-card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--acc), transparent 60%);
  opacity: .8;
}
.choice { transition: all .15s, transform .12s; }
.choice:hover { transform: translateX(4px); }
.choice:disabled:hover { transform: none; }

/* ---- score count-up ---- */
.score-giant { font-variant-numeric: tabular-nums; text-shadow: 0 0 80px rgba(200,255,0,.35); }
.score-raw-bar { max-width: 420px; margin: 26px auto 0; }
.score-raw-bar .track { height: 10px; border-radius: 100px; background: rgba(255,255,255,.07); overflow: hidden; }
.score-raw-bar .fill { height: 100%; border-radius: 100px; background: linear-gradient(90deg, #7a9b00, var(--acc)); width: 0; transition: width 1.4s .3s cubic-bezier(.2,.8,.2,1); }
.score-raw-bar .lab { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 10.5px; color: var(--faint); margin-top: 8px; letter-spacing: .14em; }

/* ---- COURSES v2 ---- */
.reco-banner {
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
  border: 1px solid rgba(200,255,0,.45); background: linear-gradient(90deg, rgba(200,255,0,.08), transparent 70%);
  border-radius: var(--r); padding: 20px 26px; margin: 0 0 30px;
}
.reco-banner .rb-score { font-family: var(--display); font-weight: 700; font-size: 44px; color: var(--acc); line-height: 1; }
.reco-banner .rb-text { flex: 1; min-width: 220px; font-size: 14.5px; color: var(--dim); }
.reco-banner .rb-text b { color: var(--text); }
.course { isolation: isolate; }
.course .c-badge {
  position: absolute; top: 18px; right: 18px; font-family: var(--mono); font-size: 9.5px;
  letter-spacing: .16em; color: #000; background: var(--acc); border-radius: 100px; padding: 5px 12px; font-weight: 700;
}
.course.recommended { border-color: var(--acc); box-shadow: 0 0 0 1px var(--acc), 0 24px 70px rgba(200,255,0,.13); }
.course .c-anchor { font-family: var(--mono); font-size: 11px; color: var(--faint); margin-top: -8px; margin-bottom: 4px; }
.course .c-anchor s { color: var(--faint); }
.course details { border-top: 1px dashed var(--line); padding: 10px 0 0; margin-top: 4px; }
.course details summary {
  cursor: pointer; font-family: var(--mono); font-size: 10.5px; letter-spacing: .16em;
  color: var(--dim); text-transform: uppercase; list-style: none; display: flex; align-items: center; gap: 8px;
}
.course details summary::before { content: "+"; color: var(--acc); font-size: 14px; transition: transform .2s; }
.course details[open] summary::before { transform: rotate(45deg); }
.course details ul { margin: 12px 0 4px; }
.course details li { font-size: 12.5px; padding-left: 16px; }
.course details li::before { content: "·"; }

.compare-wrap { margin-top: 64px; overflow-x: auto; }
.compare { width: 100%; border-collapse: collapse; min-width: 640px; }
.compare th, .compare td {
  border: 1px solid var(--line); padding: 13px 18px; text-align: center;
  font-size: 13.5px; color: var(--dim);
}
.compare th { font-family: var(--display); font-size: 15px; color: var(--text); text-transform: uppercase; letter-spacing: .04em; background: var(--panel); }
.compare td:first-child { text-align: left; font-family: var(--mono); font-size: 11.5px; letter-spacing: .08em; text-transform: uppercase; }
.compare .yes { color: var(--acc); font-weight: 700; }
.compare .no { color: var(--faint); }
.compare .hl { background: rgba(200,255,0,.05); }

.faq { margin-top: 64px; max-width: 760px; }
.faq details { border-bottom: 1px solid var(--line); padding: 20px 4px; }
.faq summary {
  cursor: pointer; font-family: var(--display); font-size: 18px; font-weight: 500;
  list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq summary::after { content: "+"; font-family: var(--mono); color: var(--acc); font-size: 20px; transition: transform .25s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--dim); font-size: 14.5px; margin-top: 12px; max-width: 640px; }

.guarantee-strip {
  margin-top: 64px; border: 1px solid var(--line); border-radius: var(--r);
  background: var(--panel); padding: 34px; display: grid; grid-template-columns: auto 1fr; gap: 26px; align-items: center;
}
.guarantee-strip .g-mark {
  width: 74px; height: 74px; border-radius: 50%; border: 2px solid var(--acc);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--display); font-weight: 700; font-size: 26px; color: var(--acc);
  box-shadow: 0 0 40px rgba(200,255,0,.2);
}
.guarantee-strip h3 { font-family: var(--display); font-size: 22px; text-transform: uppercase; margin-bottom: 6px; }
.guarantee-strip p { color: var(--dim); font-size: 14px; max-width: 700px; }
@media (max-width: 700px) { .guarantee-strip { grid-template-columns: 1fr; } }

/* ---- reduced motion ---- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001s !important; transition-duration: .001s !important; }
  .noise, .marquee-track, .footer-marquee { animation: none !important; }
}

/* ---- embedded calculator dock ---- */
#calc-dock { position: fixed; right: 0; bottom: 0; z-index: 900; }
#calc-btn {
  position: fixed; right: 22px; bottom: 22px; z-index: 901;
  font-family: var(--mono); font-size: 12px; letter-spacing: .14em;
  color: var(--acc); background: var(--bg); border: 1px solid var(--acc);
  padding: 12px 18px; cursor: pointer; border-radius: var(--r);
  transition: background .18s, color .18s, transform .18s;
}
#calc-btn:hover, #calc-btn.active { background: var(--acc); color: var(--bg); transform: translateY(-2px); }
#calc-panel {
  position: fixed; top: 0; right: 0; bottom: 0; z-index: 902;
  width: min(430px, 94vw); background: var(--bg);
  border-left: 1px solid var(--line);
  box-shadow: -28px 0 70px rgba(0,0,0,.55);
  transform: translateX(102%); transition: transform .3s cubic-bezier(.22,.8,.24,1);
  display: flex; flex-direction: column;
}
#calc-panel.open { transform: translateX(0); }
.calc-head {
  display: flex; align-items: center; gap: 10px;
  padding: 14px 18px; border-bottom: 1px solid var(--line);
}
.calc-title { font-family: var(--display); font-weight: 600; font-size: 15px; letter-spacing: .08em; }
.calc-sub { font-family: var(--mono); font-size: 10.5px; color: var(--dim); letter-spacing: .12em; text-transform: uppercase; margin-top: 2px; }
#calc-close {
  margin-left: auto; background: none; border: 1px solid var(--line); color: var(--text);
  width: 30px; height: 30px; border-radius: var(--r); cursor: pointer;
  font-size: 13px; line-height: 1; transition: border-color .18s, color .18s;
}
#calc-close:hover { border-color: var(--hot); color: var(--hot); }
#calc-host { flex: 1; min-height: 0; }
#calc-host .dcg-wrapper { background: var(--bg); }
.calc-msg {
  height: 100%; display: flex; align-items: center; justify-content: center; text-align: center;
  font-family: var(--mono); font-size: 12px; letter-spacing: .12em; color: var(--dim); padding: 30px;
}
@media (max-width: 700px) {
  #calc-btn { right: 14px; bottom: 14px; padding: 10px 14px; }
}

/* ---- course engine v2 ---- */
.cp-start { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 16px 18px; font-size: 14.5px; color: var(--dim); }
.cp-start b { color: var(--text); }
.cp-date { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); color: var(--text); font-family: var(--mono); padding: 12px 14px; font-size: 14px; width: 220px; }
.cp-date:focus { outline: none; border-color: var(--acc); }

.cp-head { display: flex; gap: 14px; flex-wrap: wrap; margin: 18px 0 14px; }
.cp-stat { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 14px 20px; min-width: 120px; }
.cp-stat .v { font-family: var(--display); font-weight: 600; font-size: 30px; line-height: 1; }
.cp-stat .v small { font-size: 15px; color: var(--dim); }
.cp-stat .k { font-family: var(--mono); font-size: 10px; letter-spacing: .14em; text-transform: uppercase; color: var(--dim); margin-top: 6px; }
.cp-stat.hot { border-color: var(--hot); }
.cp-stat.hot .v { color: var(--hot); }

.cp-bar { height: 6px; background: var(--panel); border-radius: 3px; overflow: hidden; margin-bottom: 26px; }
.cp-bar-fill { height: 100%; background: var(--acc); border-radius: 3px; transition: width .5s cubic-bezier(.22,.8,.24,1); }

.cp-today { display: flex; align-items: center; justify-content: space-between; gap: 24px; background: var(--panel); border: 1px solid var(--acc); border-radius: var(--r); padding: 26px 28px; margin-bottom: 30px; box-shadow: 0 0 50px rgba(200,255,0,.07); }
.cp-today.done { border-color: var(--line); box-shadow: none; }
.cp-today h3 { font-family: var(--display); font-size: 26px; margin: 8px 0 6px; }
.cp-today .desc b { color: var(--acc); }

.cp-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; margin-bottom: 8px; }
@media (max-width: 860px) { .cp-cols { grid-template-columns: 1fr; } .cp-today { flex-direction: column; align-items: flex-start; } }

.mg { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; }
.mg-row { display: flex; align-items: center; gap: 7px; margin-bottom: 8px; }
.mg-topic { font-family: var(--mono); font-size: 10.5px; letter-spacing: .06em; color: var(--dim); width: 130px; flex: none; text-transform: uppercase; }
.mg-cell { width: 30px; height: 22px; border-radius: 4px; border: 1px solid var(--line); background: #101010; cursor: pointer; transition: transform .15s, box-shadow .15s; }
.mg-cell:hover { transform: translateY(-2px); box-shadow: 0 4px 14px rgba(0,0,0,.5); }
.mg-cell.learning { background: #2a2a18; border-color: #4a4a22; }
.mg-cell.shaky { background: rgba(255,77,0,.25); border-color: rgba(255,77,0,.6); }
.mg-cell.solid { background: rgba(200,255,0,.18); border-color: rgba(200,255,0,.4); }
.mg-cell.mastered { background: var(--acc); border-color: var(--acc); }
.mg-legend { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 12px; font-family: var(--mono); font-size: 9.5px; letter-spacing: .08em; color: var(--dim); text-transform: uppercase; }
.mg-legend span { display: flex; align-items: center; gap: 5px; }
.mg-dot { display: inline-block; width: 10px; height: 10px; border-radius: 3px; border: 1px solid var(--line); background: #101010; }
.mg-dot.learning { background: #2a2a18; }
.mg-dot.shaky { background: rgba(255,77,0,.35); }
.mg-dot.solid { background: rgba(200,255,0,.25); }
.mg-dot.mastered { background: var(--acc); }

.cp-next { display: flex; justify-content: space-between; align-items: center; width: 100%; background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 14px 18px; margin-bottom: 10px; color: var(--text); font-size: 14px; cursor: pointer; transition: border-color .18s, transform .18s; text-align: left; }
.cp-next:hover { border-color: var(--acc); transform: translateY(-2px); }
.cp-next b { color: var(--acc); font-family: var(--mono); font-size: 13px; }

.cp-week { border: 1px solid var(--line); border-radius: var(--r); background: var(--panel); margin-bottom: 12px; padding: 0 20px; }
.cp-week summary { cursor: pointer; list-style: none; display: flex; align-items: center; gap: 14px; padding: 16px 0; font-size: 15px; }
.cp-week summary::-webkit-details-marker { display: none; }
.cpw-num { font-family: var(--display); font-weight: 600; color: var(--acc); font-size: 18px; }
.cpw-theme { color: var(--dim); }
.cp-sessions { padding: 4px 0 16px; display: flex; flex-direction: column; gap: 10px; }
.cp-session { display: flex; align-items: center; gap: 16px; background: var(--bg); border: 1px solid var(--line); border-radius: var(--r); padding: 12px 16px; }
.cp-session.done { opacity: .55; }
.cps-kind { font-family: var(--mono); font-size: 10px; letter-spacing: .1em; padding: 6px 9px; border-radius: 4px; border: 1px solid var(--line); color: var(--dim); flex: none; }
.cps-kind.sim { border-color: var(--acc); color: var(--acc); }
.cps-kind.fix { border-color: var(--hot); color: var(--hot); }
.cps-body { flex: 1; min-width: 0; }
.cps-label { font-size: 14px; font-weight: 500; }
.cps-desc { font-size: 12.5px; color: var(--dim); margin-top: 2px; }
.cps-check { font-size: 18px; color: var(--acc); }
.cps-check.dim { color: var(--dim); }
.cps-check.big { font-size: 40px; }
.cp-foot { display: flex; gap: 12px; margin: 26px 0 50px; }

.cp-autopsy { background: var(--panel); border: 1px solid var(--line); border-left: 3px solid var(--hot); border-radius: var(--r); padding: 14px 18px; margin-bottom: 10px; }
.cpa-head { font-family: var(--mono); font-size: 12px; letter-spacing: .06em; color: var(--dim); margin-bottom: 6px; }
.cpa-head b { color: var(--text); font-size: 15px; }
.cpa-text { font-size: 13.5px; color: var(--dim); }

.c-unlock { display: flex; gap: 8px; margin-bottom: 10px; }
.c-code { flex: 1; min-width: 0; background: var(--bg); border: 1px solid var(--line); border-radius: var(--r); color: var(--text); font-family: var(--mono); font-size: 12px; letter-spacing: .12em; padding: 10px 12px; text-transform: uppercase; }
.c-code:focus { outline: none; border-color: var(--acc); }
.c-code.bad { border-color: var(--hot); animation: shake .3s; }
@keyframes shake { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }

.tutor-msg { margin-top: 12px; padding: 12px 14px; background: rgba(200,255,0,.05); border: 1px solid rgba(200,255,0,.2); border-radius: var(--r); font-size: 14px; }

/* ---- hint ladder ---- */
.hint-btn { opacity: .52; margin-top: 10px; }
.hint-btn:hover { opacity: 1; }
.hint-box { background: rgba(200,255,0,.04); border: 1px solid rgba(200,255,0,.16); border-left: 3px solid var(--acc); border-radius: var(--r); padding: 12px 16px; margin-top: 10px; font-size: 14px; line-height: 1.75; }
.hint-label { display: block; font-family: var(--mono); font-size: 10px; letter-spacing: .1em; color: var(--acc); margin-bottom: 7px; opacity: .65; text-transform: uppercase; }