:root{--bg:#05091a;--bg-panel:#0a1230;--bg-card:#101c3d;--border:rgba(255,255,255,.1);--text:#eef3ff;--text-dim:#8ca8d8;--accent:#4ade80;--accent-2:#2de8c0;--success:#4ade80;--warn:#fbbf24;--font-head:'Syne',sans-serif;--font-body:'DM Sans',sans-serif;--font-mono:'JetBrains Mono',monospace;}
*{margin:0;padding:0;box-sizing:border-box;}
body{background:var(--bg);color:var(--text);font-family:var(--font-body);line-height:1.45;padding:1.4rem;}
.toolbar{max-width:900px;margin:0 auto .8rem;display:flex;gap:.6rem;justify-content:flex-end;}
.btn{font-family:var(--font-mono);font-size:.76rem;padding:.5rem .9rem;border-radius:8px;border:1px solid var(--border);background:var(--bg-card);color:var(--text);cursor:pointer;text-decoration:none;}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#05091a;}
.sheet{max-width:900px;margin:0 auto;background:linear-gradient(160deg,var(--bg-panel),var(--bg));border:1px solid var(--border);border-radius:18px;overflow:hidden;}
.head{display:flex;align-items:center;gap:1rem;padding:.95rem 1.4rem;border-bottom:1px solid var(--border);background:rgba(74,222,128,.06);}
.brand{display:inline-flex;align-items:center;gap:.5rem;text-decoration:none;color:var(--text);font-family:var(--font-head);font-weight:800;font-size:1.02rem;}
.brand b{color:var(--accent);}
.flying-logo{width:46px;height:32px;object-fit:contain;animation:fl 3.6s ease-in-out infinite;filter:drop-shadow(0 5px 12px rgba(74,222,128,.4));}
@keyframes fl{0%,100%{transform:translateY(0)}25%{transform:translateY(-6px)}50%{transform:translateY(-2px)}75%{transform:translateY(-7px)}}
.head-title{flex:1;text-align:center;}
.head-title .kind{font-family:var(--font-mono);font-size:.66rem;letter-spacing:2.5px;color:var(--accent-2);text-transform:uppercase;}
.head-title h1{font-family:var(--font-head);font-weight:800;font-size:1.5rem;line-height:1.15;}
.head-title .meta{font-family:var(--font-mono);font-size:.68rem;color:var(--text-dim);margin-top:.15rem;}
.head-title .meta em{font-style:normal;color:var(--warn);}
.score-box{font-family:var(--font-mono);font-size:.72rem;color:var(--text-dim);border:1.5px solid var(--border);border-radius:10px;padding:.4rem .8rem;text-align:center;}
.score-box b{display:block;font-size:1rem;color:var(--warn);}
.student{display:flex;gap:1.2rem;padding:.55rem 1.4rem;border-bottom:1px solid var(--border);font-size:.8rem;color:var(--text-dim);flex-wrap:wrap;}
.student span{display:inline-flex;align-items:baseline;gap:.4rem;flex:1;min-width:140px;}
.student i{font-style:normal;white-space:nowrap;}
.student u{flex:1;border-bottom:1px dashed var(--border);text-decoration:none;min-height:1rem;}
.objectives{display:flex;gap:.4rem 1.4rem;flex-wrap:wrap;padding:.55rem 1.4rem;border-bottom:1px solid var(--border);background:rgba(45,232,192,.04);}
.objectives .ob-t{font-family:var(--font-mono);font-size:.64rem;letter-spacing:1.5px;text-transform:uppercase;color:var(--accent-2);width:100%;}
.objectives span{font-size:.76rem;color:var(--text-dim);}
.objectives span::before{content:'\2713  ';color:var(--success);font-weight:700;}
.recap{padding:.55rem 1.4rem;border-bottom:1px solid var(--border);background:rgba(74,222,128,.03);}
.recap-t{font-family:var(--font-mono);font-size:.64rem;letter-spacing:1.5px;text-transform:uppercase;color:var(--accent-2);margin-bottom:.3rem;}
.recap p{font-size:.8rem;color:var(--text-dim);line-height:1.5;}
.wsbody{padding:.9rem 1.4rem;}
.part{margin-bottom:.85rem;}
.part h2{font-family:var(--font-head);font-size:.82rem;font-weight:700;letter-spacing:1px;color:var(--text);display:flex;align-items:center;gap:.5rem;margin-bottom:.5rem;}
.part h2 .emoji{font-size:1rem;}
.part h2 .marks{font-family:var(--font-mono);font-size:.62rem;color:var(--text-dim);font-weight:400;}
.diff{font-family:var(--font-mono);font-size:.58rem;padding:.12rem .5rem;border-radius:999px;font-weight:600;letter-spacing:.5px;}
.diff.g{background:rgba(74,222,128,.12);color:var(--success);border:1px solid rgba(74,222,128,.35);}
.diff.y{background:rgba(251,191,36,.1);color:var(--warn);border:1px solid rgba(251,191,36,.3);}
.diff.r{background:rgba(248,113,113,.1);color:#f87171;border:1px solid rgba(248,113,113,.35);}
.part h2::after{content:'';flex:1;height:1px;background:var(--border);}
.mcq-grid{display:grid;grid-template-columns:1fr 1fr;gap:.5rem .9rem;}
@media(max-width:640px){.mcq-grid{grid-template-columns:1fr;}}
.q{font-size:.84rem;}
.qn{font-family:var(--font-mono);font-size:.66rem;color:var(--bg);background:var(--accent-2);padding:.1rem .35rem;border-radius:4px;margin-right:.45rem;font-weight:600;}
.opts{display:flex;gap:.7rem;flex-wrap:wrap;margin:.3rem 0 0 1.45rem;color:var(--text-dim);font-size:.8rem;}
.opts label{display:inline-flex;gap:.3rem;align-items:center;cursor:pointer;}
.fill-row{display:flex;align-items:baseline;gap:.5rem;margin-bottom:.45rem;font-size:.84rem;flex-wrap:wrap;}
.blank{display:inline-block;min-width:90px;border-bottom:1.5px dashed var(--accent);}
.prob{margin-bottom:.55rem;font-size:.84rem;}
.ans-line{margin:.3rem 0 0 1.45rem;border-bottom:1.5px solid var(--border);min-height:1.5rem;display:flex;align-items:flex-end;}
.ans-line input{width:100%;background:transparent;border:none;color:var(--accent-2);font-family:var(--font-mono);font-size:.82rem;padding:.15rem 0;}
.ans-line input:focus{outline:none;}
.challenge{background:rgba(248,113,113,.05);border:1px solid rgba(248,113,113,.2);border-radius:10px;padding:.6rem .8rem;}
.viz{border:1px solid var(--border);border-radius:10px;background:var(--bg-card);padding:.4rem .7rem;margin:.2rem 0 .85rem;}
.viz svg{width:100%;max-height:150px;height:auto;display:block;}
.reflect-row{display:flex;align-items:baseline;gap:.6rem;font-size:.78rem;color:var(--text-dim);padding:.55rem 1.4rem;border-top:1px dashed var(--border);}
.reflect-row .line{flex:1;border-bottom:1px dashed var(--border);min-height:1rem;}
.foot-band{display:flex;align-items:center;gap:1.2rem;padding:.6rem 1.4rem;border-top:1px solid var(--border);font-size:.72rem;color:var(--text-dim);flex-wrap:wrap;}
.sig{flex:1;min-width:130px;text-align:center;}
.sig .line{border-top:1px solid var(--text-dim);margin-top:1.1rem;padding-top:.25rem;}
.marks-mini{font-family:var(--font-mono);border:1px solid var(--border);border-radius:8px;padding:.35rem .7rem;}
.marks-mini b{color:var(--warn);}
.keyband{padding:.5rem 1.4rem .7rem;border-top:2px dashed var(--border);}
.keyband .cut{font-family:var(--font-mono);font-size:.6rem;color:var(--text-dim);letter-spacing:2px;text-transform:uppercase;margin-bottom:.3rem;}
.keyband p{font-family:var(--font-mono);font-size:.7rem;color:var(--success);line-height:1.7;}
.foot{display:flex;justify-content:space-between;gap:1rem;padding:.55rem 1.4rem;border-top:1px solid var(--border);font-family:var(--font-mono);font-size:.68rem;color:var(--text-dim);flex-wrap:wrap;}
.foot .url{color:var(--accent-2);}
.dl-card{max-width:900px;margin:1rem auto 0;display:flex;align-items:center;gap:1rem;background:var(--bg-card);border:1px solid var(--border);border-radius:14px;padding:.9rem 1.2rem;flex-wrap:wrap;}
.dl-card .t{flex:1;min-width:220px;} .dl-card .t b{font-family:var(--font-head);} .dl-card .t span{display:block;font-size:.78rem;color:var(--text-dim);}
@media print{
  @page{size:A4;margin:9mm;}
  body{background:#fff;padding:0;-webkit-print-color-adjust:exact;print-color-adjust:exact;}
  .toolbar,.dl-card,.bwb-footer,#bwb-auth-pill,#bwb-burger{display:none;}
  .sheet{max-width:100%;border:none;border-radius:0;background:#fff;overflow:visible;}
  .head{background:#f2f6fc !important;border-color:#c9d3e3;}
  .brand,.head-title h1,.part h2{color:#0a1020;}
  .flying-logo{animation:none;filter:none;}
  .head-title .meta{color:#64748b;} .head-title .meta em{color:#b45309;}
  .score-box{border-color:#c9d3e3;color:#31435f;} .score-box b{color:#b45309;}
  .student{color:#31435f;border-color:#c9d3e3;} .student u{border-color:#7c8aa3;}
  .objectives{background:#f8fbfe !important;border-color:#c9d3e3;} .objectives span{color:#31435f;} .objectives .ob-t{color:#0369a1;}
  .part h2::after{background:#c9d3e3;} .part h2 .marks{color:#64748b;}
  .q,.prob,.fill-row{color:#0a1020;} .qn{background:#16a34a;color:#fff;}
  .opts{color:#31435f;}
  .blank{border-color:#16a34a;}
  .ans-line{border-color:#7c8aa3;} .ans-line input{color:#0a1020;}
  .challenge{background:#fdf4f4 !important;border-color:#e8c5c5;}
  .viz{background:#fff;border-color:#c9d3e3;}
  .reflect-row{color:#31435f;border-color:#c9d3e3;} .reflect-row .line{border-color:#7c8aa3;}
  .foot-band{color:#31435f;border-color:#c9d3e3;} .sig .line{border-color:#31435f;}
  .marks-mini{border-color:#c9d3e3;} .marks-mini b{color:#b45309;}
  .keyband{border-color:#94a3b8;} .keyband p{color:#047857;} .keyband .cut{color:#64748b;}
  .foot{border-color:#c9d3e3;color:#31435f;}
  .part,.q,.prob{break-inside:avoid;}
}