:root{
  --ink:#17324d;
  --ink-2:#284a68;
  --muted:#66788a;
  --paper:#f4f7fa;
  --card:#ffffff;
  --line:#dce4eb;
  --blue:#2f6fab;
  --blue-soft:#e9f2fb;
  --green:#2e7d5a;
  --green-soft:#e8f5ee;
  --amber:#a96b16;
  --amber-soft:#fff4df;
  --red:#a33d45;
  --red-soft:#fdecef;
  --shadow:0 18px 48px rgba(23,50,77,.10);
}
*{box-sizing:border-box}
html{background:var(--paper)}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--paper);line-height:1.45}
a{color:inherit;text-decoration:none}
button,select,input{font:inherit}
button{cursor:pointer}
.topbar{height:68px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 28px;position:sticky;top:0;z-index:20}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:-.02em}
.brand-mark{width:56px;height:56px;border-radius:16px;background:linear-gradient(145deg,#1c8b5f,#0e6c49);color:#fff;display:grid;place-items:center;font-size:30px;font-weight:900;box-shadow:0 10px 24px rgba(16,108,73,.2)}
.brand-mark.small{width:34px;height:34px;border-radius:10px;font-size:19px;box-shadow:none}
.topbar-actions{display:flex;gap:8px;flex-wrap:wrap}
.eyebrow,.mini-label{font-size:.74rem;text-transform:uppercase;letter-spacing:.12em;font-weight:800;color:var(--blue);margin:0 0 6px}
.mini-label{color:var(--muted);font-size:.7rem}
.muted{color:var(--muted)}
.compact{margin:4px 0 0}
.button,.ghost.small-button{border:0;border-radius:12px;padding:11px 16px;font-weight:750;display:inline-flex;align-items:center;justify-content:center;gap:8px;transition:.16s ease;background:#fff}
.button:hover,.ghost.small-button:hover{transform:translateY(-1px)}
.button:disabled{opacity:.45;cursor:not-allowed;transform:none}
.button.primary{background:var(--ink);color:#fff;box-shadow:0 8px 18px rgba(23,50,77,.18)}
.button.secondary{background:var(--blue-soft);color:var(--blue)}
.button.success{background:var(--green);color:#fff}
.button.ghost,.ghost.small-button{border:1px solid var(--line);color:var(--ink);background:#fff}
.button.full{width:100%;margin-top:12px}
.small-button{padding:8px 11px!important;font-size:.86rem}
.hero-button{font-size:1.08rem;padding:14px 22px}
.landing{min-height:100vh;background:radial-gradient(circle at 20% 10%,#dceefa 0,transparent 36%),radial-gradient(circle at 90% 90%,#e1f2e8 0,transparent 35%),var(--paper)}
.landing-shell{min-height:100vh;display:grid;place-items:center;padding:32px}
.hero-card{max-width:920px;width:100%;background:rgba(255,255,255,.92);border:1px solid rgba(220,228,235,.9);border-radius:28px;padding:54px;box-shadow:var(--shadow)}
.hero-card h1{font-size:clamp(2.4rem,6vw,4.8rem);letter-spacing:-.055em;line-height:.95;margin:20px 0 16px}
.lede{font-size:1.22rem;color:var(--ink-2);max-width:730px;margin-bottom:34px}
.mode-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}
.mode-card{padding:26px;border-radius:20px;border:1px solid var(--line);display:flex;flex-direction:column;gap:8px;min-height:190px;transition:.18s ease}
.mode-card:hover{transform:translateY(-3px);box-shadow:0 12px 30px rgba(23,50,77,.09)}
.student-card{background:linear-gradient(160deg,#fff,#eef7ff)}
.instructor-card{background:linear-gradient(160deg,#fff,#edf8f2)}
.mode-kicker{font-size:.75rem;text-transform:uppercase;letter-spacing:.12em;font-weight:800;color:var(--muted)}
.mode-card strong{font-size:1.4rem;letter-spacing:-.025em}
.mode-card span:last-child{color:var(--muted)}
.privacy-note{margin:28px 0 0;color:var(--muted);font-size:.9rem}
.app-shell{display:grid;grid-template-columns:280px 1fr;min-height:calc(100vh - 68px)}
.sidebar{background:#fff;border-right:1px solid var(--line);padding:30px 22px;display:flex;flex-direction:column;gap:24px}
.sidebar h2{margin:0;font-size:1.35rem}
.stage-list{display:flex;flex-direction:column;gap:8px}
.stage-button{width:100%;text-align:left;border:1px solid var(--line);background:#fff;border-radius:13px;padding:12px 13px;color:var(--ink);display:grid;grid-template-columns:32px 1fr;gap:10px;align-items:center}
.stage-button:hover{background:#f7fafc}
.stage-button.active{border-color:#9bc1e3;background:var(--blue-soft);box-shadow:inset 3px 0 0 var(--blue)}
.stage-num{width:28px;height:28px;border-radius:9px;background:#eff3f7;display:grid;place-items:center;font-size:.8rem;font-weight:800}
.stage-button.active .stage-num{background:#fff;color:var(--blue)}
.stage-copy strong{display:block;font-size:.9rem}.stage-copy span{display:block;font-size:.75rem;color:var(--muted);margin-top:2px}
.workbook-card{border:1px solid var(--line);border-radius:16px;padding:15px;background:#f9fbfd}
.workbook-card strong{display:block;font-size:.95rem}
.sidebar-stats{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:auto}
.sidebar-stats div{background:var(--paper);border-radius:14px;padding:12px}.sidebar-stats strong{display:block;font-size:1.3rem}.sidebar-stats span{font-size:.72rem;color:var(--muted)}
.practice-area{padding:42px;max-width:1080px;width:100%;margin:0 auto}
.practice-header{display:flex;justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:22px}.practice-header h1,.practice-header h2{margin:0;font-size:clamp(1.8rem,4vw,2.55rem);letter-spacing:-.035em}
.difficulty-pill{background:#fff;border:1px solid var(--line);border-radius:999px;padding:8px 12px;font-size:.8rem;font-weight:800;color:var(--muted);white-space:nowrap}
.instruction-card{background:#fff;border:1px solid var(--line);border-radius:24px;padding:42px;box-shadow:var(--shadow);text-align:center;min-height:390px;display:flex;flex-direction:column;align-items:center;justify-content:center}
.listen-icon{width:74px;height:74px;border-radius:22px;background:var(--blue-soft);color:var(--blue);display:grid;place-items:center;font-size:1.6rem;font-weight:900;margin-bottom:18px}
.status-label{font-size:.78rem;text-transform:uppercase;letter-spacing:.13em;font-weight:800;color:var(--muted);margin:0 0 8px}
.student-instruction-card h2{font-size:clamp(1.4rem,3vw,2.15rem);margin:0 0 20px;max-width:700px;letter-spacing:-.025em}
.primary-controls,.secondary-controls{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;margin-top:12px}
.go-banner{font-size:3.6rem;line-height:1;font-weight:950;letter-spacing:.08em;color:var(--green);margin:8px 0 10px;animation:pulse .6s ease both}
@keyframes pulse{0%{transform:scale(.7);opacity:0}100%{transform:scale(1);opacity:1}}
.hidden{display:none!important}
.revealed-instruction{max-width:760px;background:#f8fafc;border:1px dashed #b8c6d3;border-radius:14px;padding:14px 18px;margin:4px 0 6px;color:var(--ink);font-weight:700}
.option-row{display:flex;gap:14px;flex-wrap:wrap;margin:16px 0}.toggle-line{background:#fff;border:1px solid var(--line);border-radius:12px;padding:10px 13px;color:var(--ink-2);font-size:.9rem}
.tip-card{background:var(--blue-soft);border:1px solid #c6dff5;border-radius:16px;padding:18px 20px}.tip-card p{margin:5px 0 0;color:var(--ink-2)}
.settings-dialog{border:0;border-radius:20px;box-shadow:var(--shadow);padding:0;max-width:480px;width:calc(100% - 32px)}.settings-dialog::backdrop{background:rgba(23,50,77,.36)}.settings-dialog form{padding:24px;display:flex;flex-direction:column;gap:18px}.settings-dialog label{display:flex;flex-direction:column;gap:8px;font-weight:700}.settings-dialog select,.settings-dialog input[type=range]{width:100%}.settings-dialog select{border:1px solid var(--line);border-radius:10px;padding:10px;background:#fff}.dialog-header{display:flex;align-items:center;justify-content:space-between}.dialog-header h2{margin:0}.icon-button{border:0;background:transparent;font-size:1.8rem;color:var(--muted)}
.instructor-shell{display:grid;grid-template-columns:310px 1fr;min-height:calc(100vh - 68px)}
.instructor-sidebar{background:#fff;border-right:1px solid var(--line);padding:30px 24px}.instructor-sidebar h1{font-size:1.8rem;letter-spacing:-.04em;margin:0 0 8px}.instructor-sidebar .stage-list{margin:24px 0}.score-key{margin-top:24px;border-top:1px solid var(--line);padding-top:18px;font-size:.8rem;color:var(--muted);display:grid;gap:7px}.score-key kbd{display:inline-grid;place-items:center;min-width:30px;height:25px;border:1px solid var(--line);border-bottom-width:2px;border-radius:7px;background:#fff;color:var(--ink);font-weight:800;margin-right:7px}
.instructor-main{padding:38px;max-width:1120px;width:100%;margin:0 auto}
.script-card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:28px;box-shadow:var(--shadow)}
.script-meta{display:flex;justify-content:space-between;gap:20px;color:var(--blue);font-size:.72rem;letter-spacing:.1em;font-weight:900;margin-bottom:20px}
.command-text{font-size:clamp(1.5rem,3.2vw,2.5rem);font-weight:800;letter-spacing:-.035em;line-height:1.25;margin:8px 0 24px;max-width:940px}
.audio-inline{display:flex;gap:10px;flex-wrap:wrap}
.instructor-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:16px}.detail-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:21px}.correction-card{background:var(--amber-soft);border-color:#efd4a6}.detail-text{font-size:1.02rem;font-weight:650;color:var(--ink-2)}
.scoring-card{margin-top:16px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:18px 20px;display:flex;align-items:center;justify-content:space-between;gap:20px}.score-buttons{display:flex;gap:8px;flex-wrap:wrap}.score-button{width:52px;height:46px;border:1px solid var(--line);background:#fff;border-radius:12px;font-weight:900;color:var(--ink)}.score-button:hover{background:#f5f8fa}.score-button.correct{background:var(--green-soft);color:var(--green);border-color:#bddfcd}.score-button.warn{background:var(--amber-soft);color:var(--amber);border-color:#efd4a6}.score-button.danger{background:var(--red-soft);color:var(--red);border-color:#f0c1c6}
.progress-card{margin-top:16px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:20px}.progress-head{display:flex;align-items:flex-end;justify-content:space-between;gap:20px}.progress-head h3{margin:2px 0 0}.progress-bar{height:9px;border-radius:999px;background:#edf1f5;overflow:hidden;margin:15px 0}.progress-bar span{height:100%;display:block;width:0;background:linear-gradient(90deg,#2e7d5a,#5ea67f);transition:.3s}.score-summary{display:flex;gap:8px;flex-wrap:wrap}.summary-chip{border:1px solid var(--line);border-radius:999px;padding:6px 9px;font-size:.78rem;font-weight:800;background:#f9fbfc}
@media(max-width:900px){.app-shell,.instructor-shell{grid-template-columns:1fr}.sidebar,.instructor-sidebar{border-right:0;border-bottom:1px solid var(--line)}.stage-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.practice-area,.instructor-main{padding:24px}.instructor-grid{grid-template-columns:1fr}.hero-card{padding:34px}.mode-grid{grid-template-columns:1fr}.scoring-card{align-items:flex-start;flex-direction:column}}
@media(max-width:600px){.topbar{height:auto;min-height:64px;padding:12px 16px;align-items:flex-start}.topbar-actions{justify-content:flex-end}.stage-list{grid-template-columns:1fr}.practice-area,.instructor-main{padding:18px}.instruction-card{padding:26px 18px;min-height:360px}.hero-card{padding:26px 20px;border-radius:20px}.landing-shell{padding:16px}.practice-header{align-items:flex-start;flex-direction:column}.instructor-sidebar{padding:22px 18px}.command-text{font-size:1.5rem}}