/* ===========================================================
   UnB Step Prep — Design tokens
   Palette: ink navy + parchment + brass accent (clinical, exam-hall register)
   =========================================================== */
:root{
  --ink-900:#0e1a2b;
  --ink-800:#152540;
  --ink-700:#1e3358;
  --ink-600:#2c4a7c;
  --ink-500:#3f5f96;
  --paper-0:#faf7f0;
  --paper-1:#f2ede1;
  --paper-2:#e8e0cf;
  --brass-500:#a9803f;
  --brass-600:#8f6a30;
  --brass-100:#f1e3c8;
  --ok-600:#2f6b4f;
  --ok-100:#e2f0e6;
  --bad-600:#a3443a;
  --bad-100:#f6e3e0;
  --flag-600:#9c6b1f;
  --flag-100:#f7e9cf;
  --ink-muted:#5b6b85;
  --border-soft:#d9d0bb;
  --shadow-1: 0 1px 2px rgba(14,26,43,.06), 0 4px 14px rgba(14,26,43,.06);
  --shadow-2: 0 8px 30px rgba(14,26,43,.16);
  --radius-sm:6px;
  --radius-md:10px;
  --radius-lg:16px;
  --font-display:'Source Serif 4','Iowan Old Style','Georgia',serif;
  --font-body:'Inter','Segoe UI',system-ui,-apple-system,sans-serif;
  --font-mono:'IBM Plex Mono','SFMono-Regular',Consolas,monospace;
}

*,*::before,*::after{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  background:var(--paper-0);
  color:var(--ink-900);
  font-family:var(--font-body);
  -webkit-font-smoothing:antialiased;
  line-height:1.5;
}
h1,h2,h3,h4{font-family:var(--font-display); margin:0; font-weight:600; letter-spacing:-0.01em;}
p{margin:0;}
button{font-family:inherit; cursor:pointer;}
a{color:inherit;}
::selection{background:var(--brass-100);}

.sr-only{position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap;}

:focus-visible{outline:3px solid var(--brass-500); outline-offset:2px; border-radius:4px;}

#app{min-height:100vh; display:flex; flex-direction:column;}

.topbar{
  background:var(--ink-900);
  color:var(--paper-0);
  padding:14px 28px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  box-shadow:var(--shadow-1);
  z-index:20;
}
.topbar .brand{
  display:flex; align-items:baseline; gap:10px; cursor:pointer;
}
.topbar .brand .mark{
  font-family:var(--font-display); font-weight:700; font-size:1.25rem; letter-spacing:.02em;
  color:var(--brass-100);
}
.topbar .brand .tag{
  font-size:.72rem; text-transform:uppercase; letter-spacing:.12em; color:#9fb0cc;
}
.topbar .actions{display:flex; align-items:center; gap:10px;}
.pill-btn{
  background:transparent; border:1px solid rgba(250,247,240,.28); color:var(--paper-0);
  padding:7px 14px; border-radius:999px; font-size:.82rem; font-weight:500;
  transition:background .15s ease, border-color .15s ease;
  text-decoration:none; display:inline-block; cursor:pointer;
}
.pill-btn:hover{background:rgba(250,247,240,.1); border-color:rgba(250,247,240,.5);}
.pill-btn.brass{background:var(--brass-500); border-color:var(--brass-500); color:var(--ink-900); font-weight:600;}
.pill-btn.brass:hover{background:var(--brass-600);}

main{flex:1; display:flex; flex-direction:column;}

.screen{animation:fadeUp .28s ease both;}
@keyframes fadeUp{from{opacity:0; transform:translateY(6px);} to{opacity:1; transform:none;}}
@media (prefers-reduced-motion: reduce){
  .screen{animation:none;}
  *{transition-duration:0.001ms !important; animation-duration:0.001ms !important;}
}

/* ===== HOME ===== */
.home-wrap{max-width:1120px; margin:0 auto; padding:48px 28px 80px; width:100%;}
.home-hero{display:flex; align-items:flex-end; justify-content:space-between; gap:24px; margin-bottom:36px; flex-wrap:wrap;}
.home-hero h1{font-size:2.1rem; color:var(--ink-900);}
.home-hero .sub{color:var(--ink-muted); margin-top:8px; font-size:1rem; max-width:52ch;}
.stat-strip{display:flex; gap:22px; flex-wrap:wrap;}
.stat-chip{
  background:var(--paper-1); border:1px solid var(--border-soft); border-radius:var(--radius-md);
  padding:10px 18px; min-width:110px; text-align:center;
}
.stat-chip .num{font-family:var(--font-mono); font-size:1.35rem; font-weight:600; color:var(--ink-800);}
.stat-chip .lbl{font-size:.7rem; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-muted); margin-top:2px;}

.section-label{
  font-size:.75rem; text-transform:uppercase; letter-spacing:.14em; color:var(--brass-600);
  font-weight:700; margin:38px 0 14px;
}

.step-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:16px;}
@media (max-width:920px){.step-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:560px){.step-grid{grid-template-columns:1fr;}}

.step-card{
  background:var(--paper-1); border:1px solid var(--border-soft); border-radius:var(--radius-lg);
  padding:20px; cursor:pointer; text-align:left; position:relative; overflow:hidden;
  transition:transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.step-card:hover{transform:translateY(-2px); box-shadow:var(--shadow-1); border-color:var(--brass-500);}
.step-card.selected{border-color:var(--brass-500); background:var(--brass-100); box-shadow:var(--shadow-1);}
.step-card .step-name{font-family:var(--font-display); font-size:1.15rem; font-weight:700; color:var(--ink-900);}
.step-card .step-count{font-size:.82rem; color:var(--ink-muted); margin-top:4px;}
.step-card .step-bar{height:5px; border-radius:3px; background:var(--paper-2); margin-top:14px; overflow:hidden;}
.step-card .step-bar > span{display:block; height:100%; background:var(--brass-500);}

.mode-grid{display:grid; grid-template-columns:repeat(3,1fr); gap:16px;}
@media (max-width:820px){.mode-grid{grid-template-columns:1fr;}}
.mode-card{
  background:var(--ink-900); color:var(--paper-0); border-radius:var(--radius-lg); padding:22px;
  cursor:pointer; border:1px solid var(--ink-900); text-align:left;
  transition:transform .15s ease, box-shadow .15s ease;
}
.mode-card:hover{transform:translateY(-2px); box-shadow:var(--shadow-2);}
.mode-card h3{font-size:1.15rem; color:var(--paper-0);}
.mode-card p{font-size:.86rem; color:#b9c4d8; margin-top:8px; line-height:1.5;}
.mode-card .go{
  margin-top:16px; display:inline-flex; align-items:center; gap:6px; color:var(--brass-100);
  font-size:.82rem; font-weight:600; text-transform:uppercase; letter-spacing:.06em;
}

.custom-panel{
  background:var(--paper-1); border:1px solid var(--border-soft); border-radius:var(--radius-lg);
  padding:24px; margin-top:16px;
}
.field-row{display:flex; gap:20px; flex-wrap:wrap; margin-bottom:18px;}
.field{flex:1; min-width:200px;}
.field label{display:block; font-size:.76rem; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-muted); font-weight:700; margin-bottom:8px;}
.chip-set{display:flex; flex-wrap:wrap; gap:8px;}
.chip{
  border:1px solid var(--border-soft); background:var(--paper-0); border-radius:999px;
  padding:6px 13px; font-size:.82rem; color:var(--ink-800);
}
.chip.active{background:var(--ink-900); color:var(--paper-0); border-color:var(--ink-900);}
select, input[type=number]{
  width:100%; padding:9px 12px; border-radius:var(--radius-sm); border:1px solid var(--border-soft);
  background:var(--paper-0); font-family:inherit; font-size:.92rem; color:var(--ink-900);
}

.history-table{width:100%; border-collapse:collapse; margin-top:8px;}
.history-table th{
  text-align:left; font-size:.72rem; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-muted);
  padding:8px 10px; border-bottom:1px solid var(--border-soft);
}
.history-table td{padding:10px 10px; border-bottom:1px solid var(--paper-2); font-size:.88rem;}
.history-table tr:hover td{background:var(--paper-1);}
.score-badge{
  display:inline-block; padding:2px 9px; border-radius:999px; font-weight:700; font-size:.78rem;
  font-family:var(--font-mono);
}
.score-badge.high{background:var(--ok-100); color:var(--ok-600);}
.score-badge.mid{background:var(--flag-100); color:var(--flag-600);}
.score-badge.low{background:var(--bad-100); color:var(--bad-600);}

.empty-note{color:var(--ink-muted); font-size:.9rem; padding:18px 0;}

/* ===== RUNNER ===== */
.runner{flex:1; display:flex; flex-direction:column; background:var(--paper-0);}
.runner-top{
  background:var(--ink-900); color:var(--paper-0); padding:12px 26px;
  display:flex; align-items:center; justify-content:space-between; gap:20px; flex-wrap:wrap;
}
.runner-top .meta{font-size:.82rem; color:#b9c4d8;}
.runner-top .meta b{color:var(--paper-0);}
.timer{
  font-family:var(--font-mono); font-size:1.15rem; font-weight:600; padding:6px 16px;
  border-radius:999px; background:rgba(250,247,240,.08); border:1px solid rgba(250,247,240,.2);
  letter-spacing:.03em;
}
.timer.low{background:var(--bad-600); border-color:var(--bad-600); animation:pulse 1s infinite;}
@keyframes pulse{0%,100%{opacity:1;} 50%{opacity:.6;}}

.runner-body{flex:1; display:grid; grid-template-columns:250px 1fr; gap:0;}
@media (max-width:880px){.runner-body{grid-template-columns:1fr;}}

.nav-rail{
  background:var(--paper-1); border-right:1px solid var(--border-soft); padding:20px 16px;
  display:flex; flex-direction:column; gap:16px;
}
.nav-rail h4{font-size:.74rem; text-transform:uppercase; letter-spacing:.1em; color:var(--ink-muted);}
.qgrid{display:grid; grid-template-columns:repeat(5,1fr); gap:6px;}
.qgrid button{
  aspect-ratio:1; border-radius:6px; border:1px solid var(--border-soft); background:var(--paper-0);
  font-family:var(--font-mono); font-size:.76rem; font-weight:600; color:var(--ink-700);
  display:flex; align-items:center; justify-content:center; position:relative;
}
.qgrid button.answered{background:var(--ink-600); border-color:var(--ink-600); color:#fff;}
.qgrid button.flagged::after{
  content:''; position:absolute; top:-3px; right:-3px; width:8px; height:8px; border-radius:50%;
  background:var(--flag-600); border:1.5px solid var(--paper-1);
}
.qgrid button.current{outline:2px solid var(--brass-500); outline-offset:1px;}
.qgrid button.correct{background:var(--ok-600); border-color:var(--ok-600); color:#fff;}
.qgrid button.incorrect{background:var(--bad-600); border-color:var(--bad-600); color:#fff;}

.legend{display:flex; flex-direction:column; gap:6px; font-size:.75rem; color:var(--ink-muted);}
.legend .row{display:flex; align-items:center; gap:8px;}
.legend .dot{width:10px; height:10px; border-radius:3px; display:inline-block;}

.end-block-btn{
  margin-top:auto; background:var(--ink-900); color:var(--paper-0); border:none; border-radius:var(--radius-sm);
  padding:11px; font-weight:600; font-size:.86rem;
}
.end-block-btn:hover{background:var(--ink-700);}

.question-pane{padding:32px 44px 100px; max-width:820px; margin:0 auto; width:100%;}
.q-meta-row{display:flex; align-items:center; gap:10px; margin-bottom:18px; flex-wrap:wrap;}
.tag{
  font-size:.7rem; text-transform:uppercase; letter-spacing:.07em; font-weight:700;
  padding:4px 10px; border-radius:999px; background:var(--paper-2); color:var(--ink-700);
}
.tag.diff-Easy{background:var(--ok-100); color:var(--ok-600);}
.tag.diff-Moderate{background:var(--flag-100); color:var(--flag-600);}
.tag.diff-Hard{background:var(--bad-100); color:var(--bad-600);}
.flag-toggle{
  margin-left:auto; display:flex; align-items:center; gap:6px; font-size:.82rem; color:var(--ink-muted);
  border:1px solid var(--border-soft); padding:5px 12px; border-radius:999px; background:var(--paper-0);
}
.flag-toggle.on{background:var(--flag-100); color:var(--flag-600); border-color:var(--flag-600);}

.vignette{font-size:1.08rem; line-height:1.65; color:var(--ink-900); margin-bottom:26px;}

.options{display:flex; flex-direction:column; gap:10px;}
.option{
  display:flex; align-items:flex-start; gap:14px; padding:14px 16px; border-radius:var(--radius-md);
  border:1.5px solid var(--border-soft); background:var(--paper-0); text-align:left;
  transition:border-color .12s ease, background .12s ease;
}
.option:hover:not(.locked){border-color:var(--ink-500); background:var(--paper-1);}
.option .key{
  font-family:var(--font-mono); font-weight:700; color:var(--ink-700); flex:0 0 22px;
  width:22px; height:22px; border-radius:50%; border:1.5px solid var(--border-soft);
  display:flex; align-items:center; justify-content:center; font-size:.8rem; margin-top:1px;
}
.option .txt{font-size:.97rem; line-height:1.5; color:var(--ink-900);}
.option.selected{border-color:var(--ink-700); background:var(--paper-1);}
.option.selected .key{background:var(--ink-700); color:#fff; border-color:var(--ink-700);}

.option.reveal-correct{border-color:var(--ok-600); background:var(--ok-100);}
.option.reveal-correct .key{background:var(--ok-600); color:#fff; border-color:var(--ok-600);}
.option.reveal-incorrect{border-color:var(--bad-600); background:var(--bad-100);}
.option.reveal-incorrect .key{background:var(--bad-600); color:#fff; border-color:var(--bad-600);}
.option.locked{cursor:default;}

.explain-box{
  margin-top:24px; padding:20px 22px; border-radius:var(--radius-md); border:1px solid var(--border-soft);
  background:var(--paper-1); animation:fadeUp .25s ease both;
}
.explain-box .verdict{
  display:flex; align-items:center; gap:10px; font-weight:700; font-size:.95rem; margin-bottom:10px;
}
.explain-box .verdict.correct{color:var(--ok-600);}
.explain-box .verdict.incorrect{color:var(--bad-600);}
.explain-box .verdict .icon{
  width:22px; height:22px; border-radius:50%; display:flex; align-items:center; justify-content:center;
  color:#fff; font-size:.8rem;
}
.explain-box .verdict.correct .icon{background:var(--ok-600);}
.explain-box .verdict.incorrect .icon{background:var(--bad-600);}
.explain-box p{font-size:.94rem; line-height:1.6; color:var(--ink-800);}

.runner-footer{
  position:sticky; bottom:0; background:var(--paper-0); border-top:1px solid var(--border-soft);
  padding:14px 44px; display:flex; align-items:center; justify-content:space-between; gap:14px;
  max-width:820px; margin:0 auto; width:100%;
}
.btn{
  padding:10px 22px; border-radius:999px; font-weight:600; font-size:.88rem; border:1px solid var(--border-soft);
  background:var(--paper-0); color:var(--ink-800);
}
.btn:hover{background:var(--paper-1);}
.btn.primary{background:var(--ink-900); color:var(--paper-0); border-color:var(--ink-900);}
.btn.primary:hover{background:var(--ink-700);}
.btn.brass{background:var(--brass-500); color:var(--ink-900); border-color:var(--brass-500);}
.btn.brass:hover{background:var(--brass-600);}
.btn:disabled{opacity:.4; cursor:not-allowed;}

/* ===== RESULTS ===== */
.results-wrap{max-width:1000px; margin:0 auto; padding:44px 28px 90px; width:100%;}
.score-hero{
  background:var(--ink-900); color:var(--paper-0); border-radius:var(--radius-lg); padding:36px 40px;
  display:flex; align-items:center; justify-content:space-between; gap:30px; flex-wrap:wrap;
}
.score-hero .big{font-family:var(--font-mono); font-size:3.2rem; font-weight:700; color:var(--brass-100);}
.score-hero .big small{font-size:1.3rem; color:#b9c4d8; font-weight:500;}
.score-hero .label{font-size:.8rem; text-transform:uppercase; letter-spacing:.1em; color:#9fb0cc; margin-top:6px;}
.score-hero .breakdown-mini{display:flex; gap:26px; flex-wrap:wrap;}
.score-hero .mini-stat .n{font-family:var(--font-mono); font-size:1.3rem; font-weight:700;}
.score-hero .mini-stat .l{font-size:.72rem; color:#9fb0cc; text-transform:uppercase; letter-spacing:.06em;}

.bar-panel{
  background:var(--paper-1); border:1px solid var(--border-soft); border-radius:var(--radius-lg);
  padding:24px 26px; margin-top:22px;
}
.bar-row{display:flex; align-items:center; gap:14px; margin-bottom:12px;}
.bar-row .name{flex:0 0 220px; font-size:.85rem; color:var(--ink-800); font-weight:600; overflow:hidden; text-overflow:ellipsis; white-space:nowrap;}
.bar-track{flex:1; height:10px; background:var(--paper-2); border-radius:6px; overflow:hidden;}
.bar-fill{height:100%; border-radius:6px; background:var(--ink-600);}
.bar-fill.high{background:var(--ok-600);}
.bar-fill.mid{background:var(--flag-600);}
.bar-fill.low{background:var(--bad-600);}
.bar-row .pct{flex:0 0 46px; text-align:right; font-family:var(--font-mono); font-size:.82rem; color:var(--ink-muted);}

.filter-row{display:flex; gap:8px; margin:28px 0 14px;}
.filter-btn{
  border:1px solid var(--border-soft); background:var(--paper-0); border-radius:999px; padding:7px 16px;
  font-size:.82rem; color:var(--ink-700); font-weight:600;
}
.filter-btn.active{background:var(--ink-900); color:var(--paper-0); border-color:var(--ink-900);}

.review-item{
  border:1px solid var(--border-soft); border-radius:var(--radius-md); padding:20px 22px; margin-bottom:14px;
  background:var(--paper-0);
}
.review-item .rhead{display:flex; gap:10px; align-items:center; margin-bottom:10px; flex-wrap:wrap;}
.review-item .rnum{font-family:var(--font-mono); color:var(--ink-muted); font-size:.85rem;}
.review-item .verdict-pill{
  font-size:.72rem; font-weight:700; text-transform:uppercase; letter-spacing:.05em; padding:3px 10px; border-radius:999px;
}
.verdict-pill.correct{background:var(--ok-100); color:var(--ok-600);}
.verdict-pill.incorrect{background:var(--bad-100); color:var(--bad-600);}
.review-item .stem{font-size:.96rem; color:var(--ink-900); margin-bottom:12px; line-height:1.55;}
.review-item .opt-line{font-size:.88rem; padding:7px 10px; border-radius:6px; margin-bottom:5px; display:flex; gap:8px;}
.review-item .opt-line.correct-ans{background:var(--ok-100); color:var(--ok-600); font-weight:600;}
.review-item .opt-line.wrong-picked{background:var(--bad-100); color:var(--bad-600); font-weight:600;}
.review-item .explain{font-size:.88rem; color:var(--ink-800); margin-top:10px; padding-top:10px; border-top:1px dashed var(--border-soft); line-height:1.6;}

/* ===== ANALYTICS ===== */
.analytics-grid{display:grid; grid-template-columns:1fr 1fr; gap:20px; margin-top:20px;}
@media (max-width:820px){.analytics-grid{grid-template-columns:1fr;}}
.panel-card{background:var(--paper-1); border:1px solid var(--border-soft); border-radius:var(--radius-lg); padding:22px 24px;}
.panel-card h4{font-size:.8rem; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-muted); margin-bottom:16px;}

.weak-tag{
  display:inline-flex; align-items:center; gap:8px; background:var(--bad-100); color:var(--bad-600);
  padding:6px 12px; border-radius:999px; font-size:.8rem; font-weight:600; margin:4px 6px 0 0;
}

.modal-back{
  position:fixed; inset:0; background:rgba(14,26,43,.55); display:flex; align-items:center; justify-content:center;
  z-index:50; padding:20px;
}
.modal{
  background:var(--paper-0); border-radius:var(--radius-lg); padding:30px 32px; max-width:440px; width:100%;
  box-shadow:var(--shadow-2);
}
.modal h3{margin-bottom:10px;}
.modal p{color:var(--ink-muted); font-size:.92rem; margin-bottom:22px; line-height:1.55;}
.modal .row{display:flex; gap:10px; justify-content:flex-end;}

footer.foot{
  text-align:center; padding:22px; font-size:.78rem; color:var(--ink-muted);
}