@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300..700&family=Syne:wght@400..800&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #07070d;
  --s1:       #0d0d16;
  --s2:       #11111c;
  --s3:       #171724;
  --s4:       #1e1e2e;
  --border:   rgba(255,255,255,0.055);
  --border2:  rgba(255,255,255,0.10);
  --text:     #e2e2ee;
  --muted:    #7a7a96;
  --faint:    #35354d;
  --accent:   #7c6cff;
  --accenthi: #a78bfa;
  --accentbg: rgba(124,108,255,0.09);
  --accentbd: rgba(124,108,255,0.26);
  --green:    #34d399;
  --red:      #f87171;
  --orange:   #fb923c;
  --blue:     #60a5fa;
  --r-xs:3px; --r-sm:6px; --r:10px; --r-lg:14px; --r-xl:20px;
  --trans: 130ms cubic-bezier(.16,1,.3,1);
  --nav-h: 52px;
}

html { -webkit-font-smoothing:antialiased; scroll-behavior:smooth; }
body { font-family:'Inter',sans-serif; background:var(--bg); color:var(--text);
       min-height:100dvh; font-size:14px; line-height:1.6; }
a { color:inherit; text-decoration:none; }
button { cursor:pointer; font:inherit; color:inherit; border:none; background:none; }
input, select { font:inherit; color:inherit; }
::selection { background:rgba(124,108,255,.25); }
::-webkit-scrollbar { width:4px; height:4px; }
::-webkit-scrollbar-thumb { background:var(--faint); border-radius:2px; }
:focus-visible { outline:2px solid var(--accent); outline-offset:2px; border-radius:var(--r-xs); }

/* ── Nav ── */
.nav {
  height:var(--nav-h); display:flex; align-items:center; justify-content:space-between;
  padding:0 24px; border-bottom:1px solid var(--border);
  background:rgba(7,7,13,.88); backdrop-filter:blur(20px);
  position:sticky; top:0; z-index:300;
}
.nav-logo {
  font-family:'Syne',sans-serif; font-weight:800; font-size:17px;
  background:linear-gradient(120deg,var(--accenthi),var(--accent));
  -webkit-background-clip:text; -webkit-text-fill-color:transparent;
}
.nav-right { display:flex; align-items:center; gap:2px; }
.nav-link { padding:5px 12px; border-radius:var(--r-sm); color:var(--muted); font-size:13px;
            font-weight:500; transition:all var(--trans); }
.nav-link:hover { color:var(--text); background:var(--s3); }
.nav-link.active { color:var(--text); background:var(--s2); }

/* ── Buttons ── */
.btn { display:inline-flex; align-items:center; gap:6px; padding:7px 15px;
       border-radius:var(--r-sm); font-size:13px; font-weight:500;
       transition:all var(--trans); white-space:nowrap; }
.btn-primary { background:var(--accent); color:#fff; }
.btn-primary:hover { background:#6b5ce7; transform:translateY(-1px);
                     box-shadow:0 6px 20px rgba(124,108,255,.28); }
.btn-primary:active { transform:none; }
.btn-ghost  { background:transparent; border:1px solid var(--border2); color:var(--text); }
.btn-ghost:hover  { background:var(--s3); }
.btn-sm { padding:5px 11px; font-size:12px; }
.btn-xs { padding:3px 9px;  font-size:11px; }

/* ── Inputs ── */
.inp { padding:7px 12px; background:var(--s2); border:1px solid var(--border2);
       border-radius:var(--r-sm); color:var(--text); font-size:13px;
       outline:none; transition:border var(--trans); }
.inp:focus { border-color:var(--accent); }
.inp::placeholder { color:var(--faint); }
select.inp { cursor:pointer; }

/* ── Badges ── */
.badge { display:inline-flex; align-items:center; padding:2px 7px; border-radius:99px;
         font-size:11px; font-weight:600; letter-spacing:.03em; }
.badge-mcq  { background:rgba(96,165,250,.12);  color:var(--blue); }
.badge-saq  { background:rgba(52,211,153,.12);  color:var(--green); }
.badge-leq  { background:rgba(167,139,250,.12); color:var(--accenthi); }
.badge-dbq  { background:rgba(251,146,60,.12);  color:var(--orange); }
.badge-other{ background:rgba(255,255,255,.07); color:var(--muted); }

/* ── Chips ── */
.chip { display:inline-flex; align-items:center; padding:4px 11px; border-radius:99px;
        font-size:12px; font-weight:500; border:1px solid var(--border2);
        background:var(--s2); color:var(--muted); cursor:pointer;
        transition:all var(--trans); user-select:none; }
.chip:hover { border-color:var(--accentbd); color:var(--accenthi); }
.chip.on    { background:var(--accentbg); border-color:var(--accentbd); color:var(--accenthi); }

/* ── App layout ── */
.app-layout { display:flex; height:calc(100dvh - var(--nav-h)); overflow:hidden; }
.sidebar {
  width:216px; flex-shrink:0; border-right:1px solid var(--border);
  background:var(--s1); display:flex; flex-direction:column; overflow-y:auto;
}
.sb-section { padding:10px 8px; border-bottom:1px solid var(--border); }
.sb-label { font-size:10px; font-weight:700; color:var(--faint);
            letter-spacing:.08em; text-transform:uppercase; padding:0 6px; margin-bottom:6px; }
.sb-btn { display:flex; align-items:center; gap:7px; width:100%;
          text-align:left; padding:6px 9px; border-radius:var(--r-sm);
          font-size:13px; font-weight:500; color:var(--muted); transition:all var(--trans); }
.sb-btn:hover { background:var(--s3); color:var(--text); }
.sb-btn.on    { background:var(--accentbg); color:var(--accenthi); }
.sb-dot { width:7px; height:7px; border-radius:50%; flex-shrink:0; }

.main-panel { flex:1; display:flex; flex-direction:column; min-width:0; overflow:hidden; }
.main-toolbar {
  display:flex; align-items:center; gap:8px; flex-wrap:wrap;
  padding:12px 20px; border-bottom:1px solid var(--border);
  background:var(--s1); flex-shrink:0;
}
.main-content { flex:1; overflow-y:auto; padding:16px 20px; }

/* ── Question cards ── */
.q-list { display:flex; flex-direction:column; gap:7px; }
.q-card { background:var(--s1); border:1px solid var(--border);
          border-radius:var(--r-lg); overflow:hidden; transition:border-color var(--trans); }
.q-card:hover { border-color:var(--border2); }
.q-header { display:flex; align-items:center; gap:8px; padding:11px 15px;
            cursor:pointer; user-select:none; }
.q-header:hover { background:rgba(255,255,255,0.018); }
.q-title { flex:1; font-size:13px; color:var(--text); white-space:nowrap;
           overflow:hidden; text-overflow:ellipsis; }
.q-topic { font-size:11px; color:var(--faint); background:var(--s3);
           padding:2px 7px; border-radius:3px; flex-shrink:0; }
.q-arr { color:var(--faint); font-size:15px; transition:transform 180ms; flex-shrink:0; }
.q-arr.open { transform:rotate(90deg); }
.q-body { display:none; padding:0 15px 14px; }
.q-body.open { display:block; }
.q-stimulus { background:var(--s3); border-left:3px solid var(--accentbd);
              border-radius:0 var(--r-sm) var(--r-sm) 0; padding:10px 13px;
              font-size:13px; color:var(--muted); margin:10px 0 8px;
              white-space:pre-wrap; line-height:1.7; }
.q-text { font-size:13.5px; margin:10px 0 9px; white-space:pre-wrap; line-height:1.7; }
.choices { display:flex; flex-direction:column; gap:4px; margin-bottom:9px; }
.choice { display:flex; gap:9px; padding:7px 11px; border-radius:var(--r-sm);
          font-size:13px; background:var(--s2); border:1px solid var(--border); }
.choice.correct { background:rgba(52,211,153,.08); border-color:rgba(52,211,153,.22); }
.choice-letter { font-weight:700; color:var(--muted); min-width:16px; flex-shrink:0; }
.answer-box { padding:8px 12px; background:rgba(52,211,153,.07);
              border:1px solid rgba(52,211,153,.18); border-radius:var(--r-sm);
              font-size:13px; color:var(--green); margin-bottom:7px; }
.rubric-lbl { font-size:10px; font-weight:700; color:var(--faint);
              letter-spacing:.06em; text-transform:uppercase; margin-bottom:5px; }
.rubric-box { padding:11px 13px; background:var(--s3); border-radius:var(--r-sm);
              font-size:12.5px; color:var(--muted); white-space:pre-wrap;
              max-height:300px; overflow-y:auto; line-height:1.7; }

/* ── Flashcard ── */
.fc-wrap { max-width:680px; margin:0 auto; padding:4px 0 24px; }
.fc-progress { height:3px; background:var(--s4); border-radius:99px; overflow:hidden; margin-bottom:20px; }
.fc-bar { height:100%; background:linear-gradient(90deg,var(--accent),var(--accenthi));
          border-radius:99px; transition:width 350ms ease; }
.fc-card {
  background:linear-gradient(145deg,#0f0d22,#0a0919);
  border:1px solid var(--accentbd); border-radius:var(--r-xl); padding:30px 28px;
  min-height:230px; display:flex; flex-direction:column; gap:10px;
  cursor:pointer; transition:transform var(--trans), box-shadow var(--trans);
}
.fc-card:hover { transform:translateY(-2px); box-shadow:0 14px 40px rgba(124,108,255,.14); }
.fc-meta { font-size:11px; font-weight:600; color:var(--accenthi); letter-spacing:.05em; text-transform:uppercase; }
.fc-stim { font-size:12.5px; color:var(--muted); white-space:pre-wrap; line-height:1.65; }
.fc-q    { font-size:15px; font-weight:500; line-height:1.65; }
.fc-hint { font-size:12px; color:var(--faint); text-align:center; padding-top:8px; }
.fc-choices-wrap { display:flex; flex-direction:column; gap:6px; margin-top:10px; }
.fc-choice { display:flex; gap:9px; padding:9px 13px; background:var(--s2);
             border:1px solid var(--border2); border-radius:var(--r-sm);
             font-size:13px; cursor:pointer; text-align:left;
             transition:all var(--trans); width:100%; }
.fc-choice:hover { border-color:var(--accentbd); background:var(--accentbg); }
.fc-choice.correct { background:rgba(52,211,153,.09)!important; border-color:rgba(52,211,153,.32)!important; color:var(--green); }
.fc-choice.wrong   { background:rgba(248,113,113,.07)!important; border-color:rgba(248,113,113,.28)!important; color:var(--red); }
.fc-choice.reveal  { background:rgba(52,211,153,.04); border-color:rgba(52,211,153,.14); }
.fc-nav { display:flex; align-items:center; justify-content:space-between; margin-top:14px; flex-wrap:wrap; gap:8px; }
.score-pill { display:inline-flex; align-items:center; gap:5px; padding:3px 11px;
              border-radius:99px; background:var(--accentbg); border:1px solid var(--accentbd);
              color:var(--accenthi); font-size:12px; font-weight:600; }

/* ── Home ── */
.hero { text-align:center; padding:80px 24px 56px; max-width:580px; margin:0 auto; }
.hero-eyebrow { display:inline-flex; align-items:center; gap:6px; padding:4px 13px;
                border-radius:99px; background:var(--accentbg); border:1px solid var(--accentbd);
                color:var(--accenthi); font-size:12px; font-weight:600; margin-bottom:22px; }
.hero h1 { font-family:'Syne',sans-serif; font-size:clamp(32px,7vw,58px);
           font-weight:800; line-height:1.08; margin-bottom:16px; }
.grad { background:linear-gradient(120deg,var(--accenthi),var(--accent));
        -webkit-background-clip:text; -webkit-text-fill-color:transparent; }
.stat-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(170px,1fr));
             gap:10px; max-width:820px; margin:0 auto; padding:0 24px 80px; }
.stat-card { background:var(--s1); border:1px solid var(--border); border-radius:var(--r-lg);
             padding:18px 20px; transition:border-color var(--trans); }
.stat-card:hover { border-color:var(--border2); }
.stat-icon { font-size:20px; margin-bottom:8px; }
.stat-label { font-size:11px; color:var(--muted); margin-bottom:3px; }
.stat-val { font-size:17px; font-weight:700; }

/* ── Classes ── */
.classes-wrap { max-width:700px; margin:0 auto; padding:44px 24px; }
.course-card { display:block; background:var(--s1); border:1px solid var(--border);
               border-radius:var(--r-xl); padding:24px 26px; margin-bottom:11px;
               transition:all var(--trans); }
.course-card:hover { border-color:var(--accentbd); transform:translateY(-1px);
                     box-shadow:0 8px 28px rgba(124,108,255,.10); }
.course-card.dim { opacity:.28; pointer-events:none; }
.course-badges { display:flex; gap:6px; flex-wrap:wrap; margin-top:11px; }

/* ── Password overlay ── */
.pw-overlay {
  position:fixed; inset:0; background:rgba(7,7,13,.97);
  backdrop-filter:blur(24px); z-index:9999;
  display:flex; align-items:center; justify-content:center;
}
.pw-box  { width:100%; max-width:360px; padding:0 20px; }
.pw-logo { font-family:'Syne',sans-serif; font-size:32px; font-weight:800;
           background:linear-gradient(120deg,var(--accenthi),var(--accent));
           -webkit-background-clip:text; -webkit-text-fill-color:transparent;
           text-align:center; margin-bottom:28px; }
.pw-panel { background:var(--s1); border:1px solid var(--border2);
            border-radius:var(--r-xl); padding:26px 24px; }
.pw-err { background:rgba(248,113,113,.09); border:1px solid rgba(248,113,113,.28);
          color:var(--red); padding:8px 12px; border-radius:var(--r-sm);
          font-size:13px; margin-bottom:13px; display:none; }
.pw-label { font-size:11px; font-weight:600; color:var(--muted);
            letter-spacing:.06em; text-transform:uppercase; display:block; margin-bottom:6px; }

/* ── Empty ── */
.empty { text-align:center; padding:64px 20px; color:var(--muted); font-size:14px; }
.empty-icon { font-size:32px; margin-bottom:12px; }

/* ── Util ── */
.txt-muted   { color:var(--muted); }
.txt-faint   { color:var(--faint); }
.txt-accent  { color:var(--accenthi); }
.flex-center  { display:flex; align-items:center; }
.flex-between { display:flex; align-items:center; justify-content:space-between; }
.gap-2 { gap:8px; } .gap-1 { gap:4px; }
.mt-1  { margin-top:6px; } .mt-2 { margin-top:12px; }
.card  { background:var(--s1); border:1px solid var(--border); border-radius:var(--r-lg); padding:18px 20px; }