:root{
  --bg:#f4f4fb; --surface:#ffffff; --surface-2:#f0f0f8; --primary:#4338ca; --primary-dark:#3730a3; --primary-soft:#e8e7fb;
  --text:#1c1b2e; --muted:#5e5d75; --border:#e1e0ee;
  --correct:#15803d; --correct-bg:#e9f8ee; --wrong:#c62828; --wrong-bg:#fdeeee;
  --amber:#c2410c; --amber-bg:#fff3e8; --flag:#b45309;
  --radius:14px; --shadow:0 2px 10px rgba(30,27,75,.06);
  --font:'Inter',system-ui,-apple-system,'Segoe UI',sans-serif;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){
  :root{
    --bg:#0f0f1a; --surface:#191928; --surface-2:#22223a; --primary:#8b8ff5; --primary-dark:#a5a8ff; --primary-soft:#2a2a52;
    --text:#ececf6; --muted:#a3a2bd; --border:#2e2d48;
    --correct:#4ade80; --correct-bg:#12301f; --wrong:#f87171; --wrong-bg:#3a1717;
    --amber:#fb923c; --amber-bg:#3a2412; --flag:#fbbf24; --shadow:none;
    color-scheme:dark;
  }
}
*{box-sizing:border-box;margin:0;padding:0;-webkit-tap-highlight-color:transparent}
html,body{min-height:100%}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.55;font-size:16px}
button,select,input{font-family:inherit;color:inherit}
#app{max-width:720px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column}
code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.9em;background:var(--surface-2);padding:1px 5px;border-radius:5px}

.app-header{background:linear-gradient(135deg,#4338ca,#1e1b4b);color:#fff;padding:18px 16px;text-align:center;position:sticky;top:0;z-index:10}
.app-header h1{font-size:21px;font-weight:800;letter-spacing:.2px}
.tagline{font-size:12.5px;opacity:.85;margin-top:2px}

.screen{display:none;flex:1;padding:16px;animation:fade .2s ease}
.screen.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}
h2{font-size:17px;font-weight:700;margin-bottom:12px}
h2 small{display:block;font-size:12px;font-weight:500;color:var(--muted);margin-top:2px}

/* Resume */
#resume-banner{margin-bottom:14px}
.resume-card{background:var(--amber-bg);border:1px solid var(--amber);border-radius:var(--radius);padding:14px 16px;display:flex;justify-content:space-between;align-items:center;gap:12px}
.resume-card strong{color:var(--amber);font-size:15px}
.resume-sub{font-size:12.5px;color:var(--muted);margin-top:2px}
.resume-actions{display:flex;flex-direction:column;gap:6px;flex-shrink:0}
.btn-small{padding:7px 12px !important;font-size:13px !important}

/* Daily */
.daily-card{width:100%;display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:14px;background:linear-gradient(135deg,var(--amber-bg),var(--surface));border:1px solid var(--amber);border-radius:var(--radius);padding:16px 18px;cursor:pointer;box-shadow:var(--shadow);text-align:left}
.daily-card:active{transform:scale(.98)}
.daily-left{display:flex;flex-direction:column;gap:2px;min-width:0}
.daily-title{font-size:18px;font-weight:700;color:var(--amber)}
.daily-sub{font-size:13px;color:var(--muted)}
.daily-right{flex-shrink:0;font-size:15px;font-weight:700;color:var(--amber);background:var(--surface);border-radius:20px;padding:6px 12px;white-space:nowrap}
.daily-card.done{background:var(--correct-bg);border-color:var(--correct)}
.daily-card.done .daily-title{color:var(--correct)}

/* Readiness */
.readiness{margin-bottom:14px}
.ready-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px 16px;box-shadow:var(--shadow)}
.ready-head{display:flex;justify-content:space-between;align-items:baseline;gap:8px;font-weight:700;font-size:15px}
.ready-avg{font-size:22px;font-weight:800;color:var(--primary)}
.ready-avg small{font-size:11.5px;color:var(--muted);font-weight:500;margin-left:3px}
.ready-sub{font-size:13px;color:var(--muted);margin-top:6px}
.ready-track{position:relative;height:10px;border-radius:10px;margin:22px 4px 6px;background:linear-gradient(90deg,var(--wrong-bg),var(--amber-bg) 60%,var(--correct-bg))}
.ready-pass{position:absolute;top:-6px;bottom:-6px;width:2px;background:var(--text)}
.ready-pass span{position:absolute;top:-18px;left:-12px;font-size:11px;font-weight:700;color:var(--muted)}
.ready-dot{position:absolute;top:50%;width:12px;height:12px;margin:-6px 0 0 -6px;border-radius:50%;background:var(--muted);opacity:.55}
.ready-dot.latest{background:var(--primary);opacity:1;width:16px;height:16px;margin:-8px 0 0 -8px;border:2px solid var(--surface)}

/* Mode cards */
.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:14px}
.mode-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px 14px;display:flex;flex-direction:column;gap:3px;text-align:left;cursor:pointer;box-shadow:var(--shadow);transition:transform .12s ease}
.mode-card:active{transform:scale(.98)}
.mode-icon{font-size:26px}
.mode-title{font-size:16.5px;font-weight:700;color:var(--primary-dark)}
.mode-sub{font-size:12.5px;color:var(--muted);line-height:1.45}
@media (max-width:380px){ .mode-grid{grid-template-columns:1fr} }

.review-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:20px}
.review-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:12px;display:flex;flex-direction:column;align-items:center;gap:2px;cursor:pointer;box-shadow:var(--shadow);text-align:center}
.review-card.disabled-card{opacity:.45;pointer-events:none}
.rev-icon{font-size:20px}
.rev-title{font-size:14px;font-weight:700;color:var(--primary-dark)}
.rev-count{font-size:12px;color:var(--muted)}

/* Dashboard */
.dashboard{margin-bottom:22px}
.dash-list{display:flex;flex-direction:column;gap:8px}
.dash-row{display:grid;grid-template-columns:1fr 70px 40px 44px;align-items:center;gap:8px;background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:9px 12px;box-shadow:var(--shadow);cursor:pointer;text-align:left}
.dash-name{font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.dash-name b{color:var(--primary);margin-right:3px}
.dash-bar{height:8px;background:var(--border);border-radius:6px;overflow:hidden;display:block}
.dash-fill{height:100%;border-radius:6px;display:block}
.dash-fill.good{background:var(--correct)} .dash-fill.mid{background:var(--amber)} .dash-fill.low{background:var(--wrong)}
.dash-pct{font-size:13px;font-weight:700;text-align:right}
.dash-pct.good{color:var(--correct)} .dash-pct.mid{color:var(--amber)} .dash-pct.low{color:var(--wrong)}
.dash-n{font-size:11px;color:var(--muted);text-align:right}

/* History */
.history-section{margin-bottom:22px}
.history-list{display:flex;flex-direction:column;gap:9px}
.history-item{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:11px 14px;display:flex;justify-content:space-between;align-items:center;gap:10px;box-shadow:var(--shadow)}
.h-mode{font-weight:600;font-size:14px}
.h-date{font-size:12px;color:var(--muted)}
.h-score{font-size:18px;font-weight:800;color:var(--primary);white-space:nowrap}
.h-score.pass{color:var(--correct)} .h-score.fail{color:var(--wrong)}
.h-score small{font-size:11.5px;color:var(--muted);font-weight:500}
.empty-note{color:var(--muted);font-size:14px;text-align:center;padding:18px}
.clear-history{margin-top:10px;background:none;border:1px solid var(--border);color:var(--muted);padding:7px 14px;border-radius:10px;font-size:13px;cursor:pointer}

/* Settings + footer */
.settings{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px 16px;margin-bottom:18px}
.setting-row{display:flex;justify-content:space-between;align-items:center;gap:10px;font-size:14px;font-weight:500}
.setting-row input{background:var(--surface-2);border:1px solid var(--border);border-radius:8px;padding:6px 8px;font-size:14px}
.setting-actions{display:flex;gap:8px;margin-top:12px;flex-wrap:wrap}
.site-foot{font-size:12px;color:var(--muted);text-align:center;padding:4px 10px 28px;line-height:1.6}
.site-foot a{color:var(--primary)}
.install-card{width:100%;display:flex;align-items:center;justify-content:center;gap:10px;margin:0 0 20px;background:var(--surface);border:1px dashed var(--primary);border-radius:12px;padding:12px 14px;cursor:pointer;color:var(--primary-dark);font-size:14px;font-weight:600}

/* Topic lists */
.back-btn{background:none;border:none;color:var(--primary);font-size:15px;font-weight:600;cursor:pointer;margin-bottom:12px;padding:4px 0}
.topic-list{display:flex;flex-direction:column;gap:8px}
.topic-btn{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:13px 14px;text-align:left;cursor:pointer;box-shadow:var(--shadow);font-size:15px;display:flex;justify-content:space-between;align-items:center;gap:10px}
.topic-btn:active{transform:scale(.99)}
.t-key{color:var(--primary);margin-right:4px}
.t-count{font-size:12px;color:var(--muted);background:var(--surface-2);padding:3px 9px;border-radius:20px;white-space:nowrap}
.topic-group-label{font-size:12.5px;font-weight:700;color:var(--muted);margin:16px 2px 2px;text-transform:uppercase;letter-spacing:.4px;display:flex;justify-content:space-between;gap:8px}
.topic-group-label span{color:var(--primary)}
.learn-intro{font-size:13.5px;color:var(--muted);margin:-4px 2px 4px}

/* Quiz */
.quiz-topbar{display:flex;align-items:center;gap:10px;margin-bottom:14px}
.quiz-topbar .back-btn{margin:0;flex-shrink:0}
.progress-wrap{flex:1;height:7px;background:var(--border);border-radius:10px;overflow:hidden}
.progress-bar{height:100%;width:0;background:var(--primary);border-radius:10px;transition:width .3s ease}
.timer{font-size:13px;font-weight:700;color:var(--amber);white-space:nowrap;font-variant-numeric:tabular-nums}
.timer.low{color:var(--wrong)}
.q-counter{font-size:13px;color:var(--muted);font-weight:600;white-space:nowrap}
.palette-btn{background:none;border:1px solid transparent;border-radius:8px;padding:4px 6px;cursor:default}
.palette-btn.clickable{border-color:var(--border);cursor:pointer;background:var(--surface)}
.palette{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:12px;margin-bottom:12px;box-shadow:var(--shadow)}
.pal-legend{display:flex;gap:12px;font-size:12px;color:var(--muted);margin-bottom:10px;flex-wrap:wrap}
.pl::before{content:'';display:inline-block;width:10px;height:10px;border-radius:3px;border:1px solid var(--border);margin-right:4px;vertical-align:-1px}
.pl.a::before{background:var(--primary);border-color:var(--primary)}
.pl.f::before{display:none}
.pal-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(38px,1fr));gap:6px}
.pal{height:36px;border-radius:8px;border:1px solid var(--border);background:var(--surface-2);font-size:13px;font-weight:600;cursor:pointer;position:relative}
.pal.a{background:var(--primary);border-color:var(--primary);color:#fff}
.pal.f::after{content:'⚑';position:absolute;top:-6px;right:-3px;font-size:12px;color:var(--flag)}
.pal.cur{outline:2px solid var(--amber);outline-offset:1px}

.question-area{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px 16px;box-shadow:var(--shadow)}
.q-head{display:flex;justify-content:space-between;align-items:flex-start;gap:10px;margin-bottom:8px}
.q-meta{font-size:12px;color:var(--muted)}
.q-tools{display:flex;gap:6px;flex-shrink:0}
.bookmark-btn,.flag-btn{background:none;border:none;font-size:22px;cursor:pointer;color:var(--muted);line-height:1;padding:0 2px}
.bookmark-btn.on{color:var(--amber)}
.flag-btn.on{color:var(--flag)}
.q-text{font-size:17px;font-weight:600;margin-bottom:16px;line-height:1.6}
.type-chip{display:inline-block;font-size:11.5px;font-weight:700;letter-spacing:.3px;background:var(--primary-soft);color:var(--primary-dark);border-radius:6px;padding:2px 8px;margin-right:6px;vertical-align:2px;text-transform:uppercase}
.options{display:flex;flex-direction:column;gap:10px}
.option{background:var(--surface-2);border:2px solid var(--border);border-radius:12px;padding:13px 14px;text-align:left;cursor:pointer;font-size:15.5px;transition:border-color .15s ease,background .15s ease;display:flex;gap:11px;align-items:flex-start;line-height:1.5}
.option:active{transform:scale(.99)}
.opt-key{font-weight:700;color:var(--primary);flex-shrink:0;min-width:1.1em}
.option.selected{border-color:var(--primary);background:var(--primary-soft)}
.option.correct{border-color:var(--correct);background:var(--correct-bg)}
.option.correct .opt-key{color:var(--correct)}
.option.wrong{border-color:var(--wrong);background:var(--wrong-bg)}
.option.wrong .opt-key{color:var(--wrong)}
.option.disabled{pointer-events:none}

/* Ordering */
.order-label{font-size:12.5px;font-weight:700;color:var(--muted);margin:4px 2px 6px;text-transform:uppercase;letter-spacing:.3px}
.order-label span{text-transform:none;font-weight:500;letter-spacing:0}
.order-seq{list-style:none;display:flex;flex-direction:column;gap:8px;margin-bottom:14px}
.order-empty{font-size:14px;color:var(--muted);border:2px dashed var(--border);border-radius:12px;padding:14px;text-align:center}
.order-pool{display:flex;flex-direction:column;gap:8px}
.order-item{width:100%;background:var(--surface-2);border:2px solid var(--border);border-radius:12px;padding:12px 14px;text-align:left;cursor:pointer;font-size:15px;line-height:1.5;display:flex;gap:10px;align-items:flex-start}
.order-item.placed{background:var(--primary-soft);border-color:var(--primary)}
.order-item.correct{background:var(--correct-bg);border-color:var(--correct)}
.order-item.wrong{background:var(--wrong-bg);border-color:var(--wrong)}
.order-item[disabled]{cursor:default}
.ord-n{flex-shrink:0;width:24px;height:24px;border-radius:50%;background:var(--primary);color:#fff;font-size:13px;font-weight:700;display:flex;align-items:center;justify-content:center}

/* Matching */
.match-list{display:flex;flex-direction:column;gap:10px}
.match-row{background:var(--surface-2);border:2px solid var(--border);border-radius:12px;padding:11px 12px;display:flex;flex-direction:column;gap:8px}
.match-row.correct{border-color:var(--correct);background:var(--correct-bg)}
.match-row.wrong{border-color:var(--wrong);background:var(--wrong-bg)}
.match-prompt{font-size:15px;font-weight:500}
.match-row select{width:100%;padding:10px;border-radius:9px;border:1px solid var(--border);background:var(--surface);font-size:14.5px}

/* Feedback */
.feedback{margin-top:16px;padding:14px 15px;border-radius:12px;font-size:15px;animation:fade .2s ease}
.feedback.ok{background:var(--correct-bg);border:1px solid var(--correct)}
.feedback.no{background:var(--wrong-bg);border:1px solid var(--wrong)}
.f-title{font-weight:800;margin-bottom:6px}
.feedback.ok .f-title{color:var(--correct)} .feedback.no .f-title{color:var(--wrong)}
.f-exp{font-size:14.5px;line-height:1.65}
.f-notes{margin-top:10px;display:flex;flex-direction:column;gap:7px}
.note{font-size:13.5px;line-height:1.55;background:var(--surface);border-radius:9px;padding:8px 10px}
.note b{display:block;font-weight:600;color:var(--wrong)}
.note.right b{color:var(--correct)}
.note span{color:var(--muted)}
.f-sol{margin-top:10px;font-size:14px;background:var(--surface);border-radius:9px;padding:9px 12px}
.f-sol ol,.f-sol ul{padding-left:20px;margin-top:4px}
.f-foot{display:flex;justify-content:space-between;align-items:flex-start;gap:10px;margin-top:10px;font-size:12px;color:var(--muted)}
.ref{flex:1}
.report{color:var(--muted);white-space:nowrap}

.quiz-footer{margin-top:14px;display:flex;gap:10px;justify-content:space-between}
.btn-primary{flex:1;background:var(--primary);color:#fff;border:none;border-radius:12px;padding:14px;font-size:16px;font-weight:700;cursor:pointer;box-shadow:var(--shadow)}
.btn-primary:active{transform:scale(.99);background:var(--primary-dark)}
.btn-primary[disabled]{opacity:.45;cursor:not-allowed}
@media (prefers-color-scheme: dark){ .btn-primary{color:#0f0f1a} }
.btn-ghost{flex:0 0 auto;background:var(--surface);color:var(--primary);border:1px solid var(--primary);border-radius:12px;padding:14px 16px;font-size:15px;font-weight:600;cursor:pointer}

/* Study cards */
#fc-meta{margin:4px 2px 10px}
.fc-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);min-height:200px;padding:20px 18px;display:flex;flex-direction:column;gap:12px;animation:fade .2s ease}
.fc-title{font-size:18.5px;font-weight:800;color:var(--primary-dark);line-height:1.45}
.fc-body{font-size:15.5px;line-height:1.7}
.fc-ex{background:var(--amber-bg);border-left:4px solid var(--amber);border-radius:8px;padding:11px 14px;font-size:14.5px;line-height:1.65}
.fc-ex b{display:block;color:var(--amber);font-size:12.5px;margin-bottom:3px;text-transform:uppercase;letter-spacing:.3px}

/* Score */
.score-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px 18px;text-align:center;box-shadow:var(--shadow);margin-bottom:18px}
.score-big{font-size:48px;font-weight:800;color:var(--primary);line-height:1.1}
.score-big.pass{color:var(--correct)} .score-big.fail{color:var(--wrong)}
.score-big small{font-size:20px;color:var(--muted);font-weight:600}
.verdict{display:inline-block;margin-top:8px;font-weight:800;letter-spacing:1px;padding:3px 14px;border-radius:20px;font-size:14px}
.verdict span{font-weight:500;letter-spacing:0;font-size:12px}
.verdict.pass{background:var(--correct-bg);color:var(--correct)} .verdict.fail{background:var(--wrong-bg);color:var(--wrong)}
.score-pct{font-size:14.5px;color:var(--muted);margin-top:6px}
.part-table{margin:16px 0 4px;text-align:left}
.part-cap{font-size:12.5px;font-weight:700;text-transform:uppercase;letter-spacing:.3px;color:var(--muted);margin-bottom:4px}
.part-row{display:flex;justify-content:space-between;gap:10px;padding:8px 2px;border-bottom:1px solid var(--border);font-size:13.5px}
.part-row span:last-child{white-space:nowrap;color:var(--muted)}
.meets{color:var(--correct)} .needs{color:var(--wrong)}
.score-note{font-size:12px;color:var(--muted);margin-top:10px;text-align:left}

/* Answer review */
.explanations h3{font-size:17px;margin-bottom:10px}
.rv-filter{display:flex;gap:8px;margin-bottom:12px;flex-wrap:wrap}
.chip{background:var(--surface);border:1px solid var(--border);border-radius:20px;padding:7px 14px;font-size:13px;cursor:pointer;color:var(--muted)}
.chip.on{background:var(--primary);border-color:var(--primary);color:#fff}
@media (prefers-color-scheme: dark){ .chip.on{color:#0f0f1a} }
#rv-list.only-bad .exp-item.st-ok{display:none}
#rv-list.only-flag .exp-item:not(.flagged){display:none}
.exp-item{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:14px;margin-bottom:12px;box-shadow:var(--shadow)}
.exp-item.st-ok{border-left:4px solid var(--correct)} .exp-item.st-no{border-left:4px solid var(--wrong)} .exp-item.st-skip{border-left:4px solid var(--amber)}
.exp-head{display:flex;align-items:center;gap:8px;margin-bottom:8px}
.exp-num{font-weight:700;color:var(--muted);font-size:13px}
.exp-badge{font-size:12px;font-weight:700;padding:3px 10px;border-radius:20px}
.exp-badge.ok{background:var(--correct-bg);color:var(--correct)} .exp-badge.no{background:var(--wrong-bg);color:var(--wrong)} .exp-badge.skip{background:var(--amber-bg);color:var(--amber)}
.exp-flag{color:var(--flag)}
.exp-task{margin-left:auto;font-size:12px;color:var(--primary);font-weight:700}
.exp-q{font-weight:600;margin-bottom:8px;font-size:15px}
.rv-opts{display:flex;flex-direction:column;gap:6px;margin:6px 0 4px;font-size:14px}
.rv-opt{padding:7px 10px;border-radius:8px;background:var(--surface-2);line-height:1.5}
.rv-opt.right{background:var(--correct-bg);color:var(--correct);font-weight:600}
.rv-opt.picked{background:var(--wrong-bg);color:var(--wrong)}
.rv-note{font-size:12.5px;color:var(--muted);font-weight:400;margin-top:2px}
.rv-tag{font-size:12px;font-weight:700;margin-left:4px}
.rv-cols{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.rv-cols ol{padding-left:18px;margin-top:4px}
.rv-cols li.ok{color:var(--correct)} .rv-cols li.bad{color:var(--wrong)}
.rv-match div{padding:5px 0;border-bottom:1px dashed var(--border)}
.rv-match .ok{color:var(--correct)} .rv-match .bad{color:var(--wrong)}
.exp-detail{margin-top:9px;font-size:14px;line-height:1.65;border-top:1px dashed var(--border);padding-top:9px}
.exp-detail .lab{font-weight:700;color:var(--primary)}
.score-actions{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin:18px 0 40px}
.btn-share{flex:0 0 auto;background:#25d366;color:#fff;border:none;border-radius:12px;padding:14px 18px;font-size:15px;font-weight:700;cursor:pointer}
.btn-share[disabled]{opacity:.6}