:root{
  --bg:#f4f6f8; --panel:#fff; --ink:#182132; --muted:#667085; --line:#dde2e8;
  --accent:#172033; --accent-2:#42526b; --soft:#eef2f6; --ok:#127a4f; --ok-bg:#eaf7f0;
  --bad:#b42318; --bad-bg:#fff0ee; --warn:#9a6700; --warn-bg:#fff7df; --blue:#315b8a;
  --shadow:0 12px 35px rgba(24,33,50,.07); --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.5 Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif}
button,input{font:inherit}
button{color:inherit}
.shell{width:min(1120px,calc(100% - 32px));margin:0 auto}
.site-header{position:sticky;top:0;z-index:20;background:rgba(244,246,248,.9);backdrop-filter:blur(14px);border-bottom:1px solid rgba(221,226,232,.8)}
.header-inner{height:72px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{display:flex;align-items:center;gap:11px;color:var(--ink);text-decoration:none}
.brand-mark{width:38px;height:38px;border-radius:11px;background:var(--accent);color:#fff;display:grid;place-items:center;font-weight:900;font-size:20px}
.brand strong,.brand small{display:block}.brand strong{font-size:15px}.brand small{font-size:12px;color:var(--muted);margin-top:1px}
.nav{display:flex;gap:4px;background:#e9edf2;border-radius:12px;padding:4px}.nav-btn{border:0;background:transparent;border-radius:9px;padding:8px 13px;font-weight:750;font-size:14px;cursor:pointer}.nav-btn.active{background:#fff;box-shadow:0 1px 4px rgba(16,24,40,.08)}
.main-shell{padding-top:32px;padding-bottom:64px;min-height:calc(100vh - 126px)}
.hidden{display:none!important}.view{animation:fade .14s ease-out}@keyframes fade{from{opacity:.65;transform:translateY(2px)}to{opacity:1;transform:none}}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px}
.hero-grid{display:grid;grid-template-columns:1.18fr .82fr;gap:18px}.hero-panel{padding:32px}.hero-panel h1,.page-heading h1,.summary-panel h1{font-size:clamp(30px,4vw,46px);line-height:1.08;letter-spacing:-.035em;margin:8px 0 14px}.lede{font-size:18px;color:#475467;max-width:720px;margin:0}
.eyebrow{text-transform:uppercase;letter-spacing:.12em;font-size:11px;font-weight:850;color:#667085}.hero-actions{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin-top:24px}.microcopy{font-size:13px;color:var(--muted);margin-top:18px}
.btn{border:0;border-radius:11px;padding:11px 16px;font-weight:800;cursor:pointer;transition:transform .08s ease,opacity .15s ease,background .15s ease}.btn:hover{transform:translateY(-1px)}.btn:disabled{opacity:.45;cursor:not-allowed;transform:none}.btn-primary{background:var(--accent);color:#fff}.btn-secondary{background:var(--soft);color:var(--ink);border:1px solid #dce2e8}.btn-danger{background:#fff0ee;color:var(--bad);border:1px solid #f1c7c2}
.muted{color:var(--muted)}.small{font-size:13px}
.panel-heading,.section-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:18px}.panel-heading h2,.section-heading h2{margin:3px 0 0;font-size:22px;letter-spacing:-.02em}.section-heading{margin-bottom:15px}.section-heading>p{margin:5px 0 0;color:var(--muted);font-size:14px;max-width:520px;text-align:right}.section-block{margin-top:28px}.page-heading{margin-bottom:22px}.page-heading h1{margin-top:5px}.page-heading>p{max-width:560px}
.storage-badge,.pass-key,.chip{font-size:12px;font-weight:750;color:#526070;background:var(--soft);padding:6px 9px;border-radius:999px;white-space:nowrap}.pass-key{background:transparent}.pass-key i{display:inline-block;width:14px;border-top:2px dashed #98a2b3;vertical-align:middle;margin-right:5px}
.metric-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-top:18px}.metric{background:#f7f8fa;border:1px solid #e9edf1;border-radius:14px;padding:14px}.metric span{display:block;color:var(--muted);font-size:12px;font-weight:700}.metric b{display:block;font-size:25px;margin-top:3px;letter-spacing:-.03em}.metric small{display:block;color:var(--muted);margin-top:2px}
.level-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:10px}.level-card{position:relative;background:#fff;border:1px solid var(--line);border-radius:15px;padding:15px;min-height:174px;display:flex;flex-direction:column}.level-card.locked{opacity:.5;background:#f8f9fa}.level-top{display:flex;align-items:center;justify-content:space-between}.level-num{font-size:20px;font-weight:900}.lock{font-size:12px;color:var(--muted)}.level-card h3{font-size:14px;margin:12px 0 6px}.level-card p{font-size:12px;color:var(--muted);margin:0 0 12px}.level-card .level-stats{font-size:11px;color:#667085;margin-top:auto}.level-card .mini-start{margin-top:10px;width:100%;padding:8px 10px;font-size:12px}.level-card.current{border-color:#9aacbf;box-shadow:0 0 0 2px #dfe7ef inset}
.two-col{display:grid;grid-template-columns:1.15fr .85fr;gap:18px}.chart-wrap{min-height:220px;margin-top:14px}.tall-chart{min-height:270px}.empty-state{height:210px;display:grid;place-items:center;text-align:center;color:var(--muted);background:#f8f9fa;border-radius:14px;border:1px dashed #d7dde5;padding:24px}
.chart-svg{width:100%;height:220px;display:block}.chart-svg text{font-size:10px;fill:#7a8594}.chart-svg .grid{stroke:#e6eaef;stroke-width:1}.chart-svg .pass{stroke:#98a2b3;stroke-width:1.5;stroke-dasharray:5 5}.chart-svg .line{fill:none;stroke:var(--blue);stroke-width:3;stroke-linecap:round;stroke-linejoin:round}.chart-svg .dot{fill:#fff;stroke:var(--blue);stroke-width:2}.chart-svg .dot.pass-dot{fill:#dff3e8;stroke:var(--ok)}
.bar-stack{display:grid;gap:16px;margin-top:20px}.bar-row{display:grid;grid-template-columns:135px 1fr 50px;gap:10px;align-items:center}.bar-label{font-size:13px;font-weight:700}.bar-track{height:11px;background:#edf0f3;border-radius:999px;overflow:hidden}.bar-fill{height:100%;background:#596b83;border-radius:999px}.bar-value{text-align:right;font-weight:800;font-size:13px}.bar-note{grid-column:2/-1;font-size:11px;color:var(--muted);margin-top:-7px}.compact-bars{max-width:650px}
.session-shell{max-width:930px;margin:0 auto}.session-topline{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:10px}.session-meta{display:flex;align-items:center;gap:12px;font-size:13px;font-weight:750;color:#5d6978}.text-btn{border:0;background:transparent;padding:6px 0;cursor:pointer;color:#526070;font-weight:750}.progress-track{height:8px;border-radius:999px;background:#e6eaf0;overflow:hidden;margin-bottom:16px}.progress-track>div{height:100%;width:0;background:#60738e;transition:width .2s ease}
.question-panel{padding:28px}.context{background:#f7f8fa;border:1px solid #e4e8ed;border-radius:14px;padding:18px 20px;white-space:pre-line;font-size:16px;line-height:1.58}.stem{font-size:22px;line-height:1.32;margin:22px 0 16px;letter-spacing:-.015em}.options{display:grid;gap:10px}.option{width:100%;display:flex;align-items:flex-start;gap:12px;text-align:left;border:1px solid var(--line);border-radius:13px;background:#fff;padding:13px 14px;cursor:pointer}.option:hover{background:#fafbfc}.option.selected{outline:3px solid #c7d3df;border-color:#9daebe}.option:disabled{cursor:default}.letter{width:29px;height:29px;border-radius:50%;display:grid;place-items:center;flex:0 0 auto;background:#eef2f6;font-weight:850}.feedback{margin-top:16px;padding:14px 16px;border-radius:13px;text-align:center;font-size:22px;font-weight:900}.feedback.right{background:var(--ok-bg);color:var(--ok)}.feedback.wrong{background:var(--bad-bg);color:var(--bad)}.question-footer{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-top:18px}.timer{font-variant-numeric:tabular-nums;color:var(--muted);font-weight:750}.actions{display:flex;align-items:center;gap:10px}.keyboard-hint{font-size:12px;color:#98a2b3}
.summary-panel{max-width:820px;margin:28px auto}.summary-metrics{grid-template-columns:repeat(4,1fr);margin:22px 0}.notice{padding:15px 17px;border-radius:13px;margin:18px 0}.notice.success{background:var(--ok-bg);color:#145c40}.notice.warn{background:var(--warn-bg);color:#755000}.notice strong{display:block;margin-bottom:2px}
.dashboard-metrics{grid-template-columns:repeat(5,1fr);margin:0}.table-wrap{overflow-x:auto;background:#fff;border:1px solid var(--line);border-radius:15px;box-shadow:var(--shadow)}table{width:100%;border-collapse:collapse;font-size:14px}th,td{padding:11px 13px;border-bottom:1px solid #edf0f3;text-align:left;white-space:nowrap}th{font-size:11px;text-transform:uppercase;letter-spacing:.07em;color:#6f7b8a;background:#fafbfc}tr:last-child td{border-bottom:0}.score-pass{color:var(--ok);font-weight:800}.score-not{font-weight:750}.table-empty{padding:26px;color:var(--muted);text-align:center}
.data-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.data-grid h2{margin-top:0}.data-grid p{color:var(--muted);min-height:96px}.danger-panel{border-color:#f1d2ce}.file-btn{display:inline-block;position:relative;overflow:hidden}.file-btn input{position:absolute;inset:0;opacity:0;cursor:pointer}.status-line{font-size:13px;color:var(--muted);margin-top:12px;min-height:20px}.data-summary{display:flex;gap:10px;flex-wrap:wrap}.data-pill{background:#f2f4f7;border-radius:999px;padding:7px 10px;font-size:12px;font-weight:750;color:#566271}
.site-footer{border-top:1px solid var(--line);color:#7d8794;font-size:12px;padding:20px 0 28px}
@media(max-width:980px){.hero-grid,.two-col{grid-template-columns:1fr}.level-grid{grid-template-columns:repeat(4,1fr)}.dashboard-metrics{grid-template-columns:repeat(3,1fr)}.data-grid{grid-template-columns:1fr}.data-grid p{min-height:0}.section-heading>p{text-align:left}.section-heading{flex-direction:column;gap:4px}}
@media(max-width:650px){.shell{width:min(100% - 20px,1120px)}.header-inner{height:auto;padding:10px 0;align-items:flex-start}.brand small{display:none}.nav-btn{padding:7px 9px;font-size:12px}.main-shell{padding-top:18px}.panel,.hero-panel,.question-panel{padding:18px}.hero-panel h1,.page-heading h1,.summary-panel h1{font-size:32px}.lede{font-size:16px}.level-grid{grid-template-columns:repeat(2,1fr)}.metric-grid,.summary-metrics,.dashboard-metrics{grid-template-columns:repeat(2,1fr)}.question-footer{align-items:flex-end}.keyboard-hint{display:none}.stem{font-size:20px}.bar-row{grid-template-columns:110px 1fr 44px}.session-topline{align-items:flex-start}.session-meta{gap:7px;flex-wrap:wrap;justify-content:flex-end}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;animation:none!important;transition:none!important}}