:root{
  --navy:#071b2c;--navy2:#0a3146;--blue:#0e7490;--blue2:#1499a7;--sea:#14a1a8;
  --foam:#edf9f8;--spray:#d9f2f1;--ink:#102732;--muted:#5d727b;--line:#d1e3e5;
  --good:#14724b;--bad:#b33838;--warn:#9a6700;--card:#fff;--bg:#edf5f6;--gold:#f5c84c;
  --shadow:0 18px 50px rgba(7,35,48,.12)
}
*{box-sizing:border-box}
html{min-height:100%;background:var(--bg)}
body{margin:0;min-height:100%;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:
  radial-gradient(circle at 8% 18%,rgba(20,161,168,.09),transparent 23rem),
  radial-gradient(circle at 92% 36%,rgba(14,116,144,.07),transparent 27rem),
  linear-gradient(180deg,#dff1f2 0,#f7fafb 34rem,#edf5f6 100%);color:var(--ink)
}
body::before{content:"";position:fixed;inset:0;pointer-events:none;opacity:.24;background-image:
  linear-gradient(rgba(26,116,132,.07) 1px,transparent 1px),
  linear-gradient(90deg,rgba(26,116,132,.07) 1px,transparent 1px);background-size:52px 52px;mask-image:linear-gradient(to bottom,#000 0,transparent 65%)}
.site-header,header{position:relative;overflow:hidden;background:linear-gradient(125deg,#061827 0%,#0a3348 52%,#0d6c78 100%);color:white;padding:30px 20px 44px;box-shadow:0 10px 34px rgba(3,24,34,.24)}
.site-header::before,header::before{content:"";position:absolute;inset:0;pointer-events:none;background:
  radial-gradient(circle at 82% 24%,rgba(255,255,255,.09) 0 2px,transparent 3px),
  repeating-radial-gradient(circle at 82% 24%,transparent 0 44px,rgba(187,238,240,.08) 45px 46px,transparent 47px 78px),
  linear-gradient(115deg,transparent 0 70%,rgba(255,255,255,.055) 70% 70.5%,transparent 70.5%)}
.wrap{position:relative;z-index:1;max-width:1080px;margin:auto}.brand{display:flex;gap:14px;align-items:center}.mark{width:52px;height:52px;border:1px solid rgba(188,238,231,.65);border-radius:16px;display:grid;place-items:center;font-size:28px;background:linear-gradient(145deg,rgba(255,255,255,.12),rgba(255,255,255,.035));box-shadow:inset 0 1px 0 rgba(255,255,255,.15),0 8px 28px rgba(0,0,0,.12)}.eyebrow{font-size:.76rem;letter-spacing:.15em;text-transform:uppercase;color:#aee9e8;font-weight:900}h1{font-size:clamp(2rem,5vw,3.3rem);line-height:1;margin:4px 0 8px;letter-spacing:-.045em}header p{max-width:760px;margin:5px 0 0;color:#d9eff1;line-height:1.55;font-size:1.02rem}
main{position:relative;z-index:2;max-width:1080px;margin:-22px auto 52px;padding:0 20px}.panel{background:rgba(255,255,255,.97);border:1px solid rgba(189,215,220,.9);border-radius:20px;box-shadow:var(--shadow);backdrop-filter:blur(10px)}
.toolbar{display:flex;gap:12px;flex-wrap:wrap;justify-content:space-between;align-items:center;padding:16px 18px;border-bottom:1px solid var(--line)}.stats{display:flex;gap:18px;flex-wrap:wrap}.stat b{display:block;font-size:1.08rem}.stat span{font-size:.72rem;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-weight:900}.actions{display:flex;gap:8px;flex-wrap:wrap}button{font:inherit}.btn{border:0;border-radius:11px;padding:10px 15px;font-weight:850;cursor:pointer;transition:transform .12s ease,box-shadow .12s ease,background .12s ease}.btn:hover{transform:translateY(-1px)}.btn.primary{background:linear-gradient(135deg,#0c617f,#0e8e99);color:white;box-shadow:0 8px 20px rgba(12,97,127,.22)}.btn.primary:hover{box-shadow:0 10px 24px rgba(12,97,127,.3)}.btn.secondary{background:#e9f2f4;color:var(--ink);border:1px solid #d3e3e6}.btn.game-cta{display:inline-flex;align-items:center;gap:8px;background:linear-gradient(135deg,#f7cf58,#efb83b);color:#2d260d;border:1px solid #e5b53c;box-shadow:0 8px 20px rgba(176,122,8,.18)}.btn.danger{background:#fff1f1;color:#8c2525}.btn:disabled{opacity:.45;cursor:not-allowed;transform:none}.btn:focus-visible,.option:focus-within,.qdot:focus-visible{outline:3px solid rgba(20,161,168,.35);outline-offset:2px}
.progress{height:7px;background:#e7eff1}.progress>div{height:100%;background:linear-gradient(90deg,var(--sea),#2ea4a5);transition:width .2s}.layout{display:grid;grid-template-columns:220px 1fr;min-height:560px}.nav{border-right:1px solid var(--line);padding:18px;background:linear-gradient(180deg,#f8fbfc,#f2f7f8)}.nav h2{font-size:.82rem;margin:0 0 12px;color:var(--muted);text-transform:uppercase;letter-spacing:.09em}.qgrid{display:grid;grid-template-columns:repeat(5,1fr);gap:7px}.qdot{aspect-ratio:1;border-radius:9px;border:1px solid var(--line);background:white;font-weight:800;cursor:pointer;color:#36505c}.qdot.answered{background:#dff2ef;border-color:#96cbc5}.qdot.current{outline:3px solid #1b7f8f55;border-color:#1b7f8f}.qdot.correct{background:#e0f4e7;border-color:#77b58c;color:var(--good)}.qdot.wrong{background:#fae5e5;border-color:#d99a9a;color:var(--bad)}
.content{padding:30px 32px 32px}.category,.kicker{display:inline-flex;border-radius:999px;background:#e8f4f5;color:#22656e;padding:5px 10px;font-size:.72rem;font-weight:900;text-transform:uppercase;letter-spacing:.07em}.kicker{background:#dff2f0;color:#17616b}.qtitle{font-size:clamp(1.25rem,2.7vw,1.7rem);line-height:1.35;margin:14px 0 20px}.options{display:grid;gap:11px}.option{display:grid;grid-template-columns:38px 1fr;gap:12px;align-items:start;border:1px solid #c8dadd;border-radius:14px;padding:14px;background:white;cursor:pointer;transition:.15s;box-shadow:0 2px 0 rgba(10,54,68,.02)}.option:hover{border-color:#75aeb5;background:#f8fcfc;transform:translateY(-1px)}.option.selected{border-color:#1a7180;background:#edf8f8;box-shadow:0 0 0 2px #1a71801c}.option.correct{border-color:#5ca276;background:#edf9f0}.option.wrong{border-color:#d07878;background:#fff2f2}.letter{width:31px;height:31px;border-radius:50%;background:#eef3f4;display:grid;place-items:center;font-weight:900}.option.selected .letter{background:#1a7180;color:white}.option.correct .letter{background:var(--good);color:white}.option.wrong .letter{background:var(--bad);color:white}.option input{position:absolute;opacity:0;pointer-events:none}.feedback{margin-top:18px;padding:15px 16px;border-radius:12px;background:#f5f8f9;border:1px solid var(--line);line-height:1.5}.feedback.good{background:#edf9f0;border-color:#b5ddc2}.feedback.bad{background:#fff2f2;border-color:#ebc0c0}.navbuttons{display:flex;justify-content:space-between;gap:12px;margin-top:24px}.navbuttons .right{display:flex;gap:8px}.small{font-size:.84rem;color:var(--muted)}
.question-media{margin:-4px 0 20px;border:1px solid #cde0e3;border-radius:15px;background:linear-gradient(180deg,#f7fbfc,#edf7f8);padding:14px;display:grid;place-items:center;box-shadow:inset 0 1px 0 #fff}.diagram-card{width:min(100%,440px);text-align:center}.diagram-card svg{display:block;width:100%;height:auto;max-height:240px;margin:auto}.diagram-note{font-size:.73rem;color:var(--muted);margin-top:7px}.signal-box{width:min(100%,440px);display:flex;flex-direction:column;align-items:center;gap:10px;padding:12px}.signal-icon{font-size:2.3rem;line-height:1}.signal-play{border:0;border-radius:10px;padding:10px 16px;background:linear-gradient(135deg,#0c5a7a,#118f99);color:white;font-weight:850;cursor:pointer}.signal-play:disabled{opacity:.6}.signal-help{font-size:.78rem;color:var(--muted);text-align:center;line-height:1.4}.review-item .question-media{margin:10px 0 12px;padding:9px}.review-item .diagram-card{max-width:330px}.review-item .signal-box{padding:4px}.page-ref{display:inline-block;margin-top:5px;font-size:.76rem;color:var(--muted)}
.intro{padding:30px 32px 34px}.introgrid{display:grid;grid-template-columns:1.3fr .7fr;gap:28px;align-items:start}.intro h2{font-size:1.68rem;margin:8px 0 10px;letter-spacing:-.02em}.intro p{line-height:1.65;color:#40535d}.rules{background:linear-gradient(145deg,#eff9f8,#e7f4f4);border:1px solid #cce4e2;border-radius:16px;padding:19px;box-shadow:inset 0 1px 0 #fff}.rules b{display:block;margin-bottom:8px}.rules ul{margin:8px 0 0;padding-left:20px;color:#3e565c;line-height:1.58}.startbox{display:flex;gap:9px;align-items:center;flex-wrap:wrap;margin-top:20px}.check{display:flex;gap:8px;align-items:center;font-size:.9rem;color:#4b5d65}.check input{width:18px;height:18px}
.result{padding:30px}.scorebox{text-align:center;padding:18px 12px 26px}.score{font-size:clamp(3.9rem,12vw,5.2rem);line-height:1;font-weight:950;letter-spacing:-.065em}.pass{color:var(--good)}.fail{color:var(--bad)}.result h2{text-align:center;margin:8px 0}.result .sub{text-align:center;color:var(--muted);max-width:670px;margin:0 auto 22px;line-height:1.5}.breakdown{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:22px auto;max-width:700px}.breakdown div{border:1px solid var(--line);border-radius:13px;padding:14px;text-align:center;background:#f9fbfb}.breakdown b{font-size:1.4rem;display:block}.review-item{border-top:1px solid var(--line);padding:18px 2px}.review-item h3{font-size:1rem;margin:0 0 8px}.review-item p{margin:5px 0;line-height:1.5}.review-item .your{color:var(--bad)}.review-item .rightans{color:var(--good);font-weight:700}.review-item.ok .your{color:var(--good)}
footer{max-width:1080px;margin:0 auto 44px;padding:0 20px;color:#64757c;font-size:.78rem;line-height:1.55}footer a{color:#275f70}.footer-credit{margin-top:5px;font-size:.72rem;color:#839197}.footer-credit a{font-weight:700}.hidden{display:none!important}
.progress-meter{display:block;width:100%;height:7px;border:0;border-radius:0;background:#e7eff1;appearance:none;-webkit-appearance:none}.progress-meter::-webkit-progress-bar{background:#e7eff1}.progress-meter::-webkit-progress-value{background:linear-gradient(90deg,var(--sea),#2ea4a5);transition:width .2s}.progress-meter::-moz-progress-bar{background:linear-gradient(90deg,var(--sea),#2ea4a5)}.center-actions{justify-content:center}.review-heading{text-align:left}a.btn{display:inline-flex;align-items:center;justify-content:center;text-decoration:none}header h1 a.header-home-link{color:inherit;text-decoration:none}header h1 a.header-home-link:hover,header h1 a.header-home-link:focus-visible{text-decoration:underline;text-underline-offset:.12em}
@media(max-width:760px){main{padding:0 10px}.layout{grid-template-columns:1fr}.nav{border-right:0;border-bottom:1px solid var(--line);padding:12px 16px}.nav h2{display:none}.qgrid{grid-template-columns:repeat(10,1fr);gap:5px}.qdot{border-radius:6px;font-size:.75rem}.content,.intro,.result{padding:20px 17px}.introgrid{grid-template-columns:1fr}.toolbar{align-items:flex-start}.stats{gap:12px}.breakdown{grid-template-columns:1fr}.option{grid-template-columns:34px 1fr;padding:12px}.navbuttons{position:sticky;bottom:0;background:#ffffffee;backdrop-filter:blur(7px);padding:10px 0 2px}.hide-mobile{display:none}.site-header,header{padding:24px 16px 38px}.mark{width:46px;height:46px;border-radius:14px}.btn{padding:10px 12px}}
.clipboard-helper{position:fixed;left:-10000px;top:-10000px;width:1px;height:1px;opacity:0}