:root{--navy:#0E2A5C;--teal:#1A9A9A;--gold:#C9A646;--cyan:#5FE0E8;--paper:#EEF8F9;--ink:#10213f;--line:#bcd6da;--bad:#9b1c1c;--good:#0b6b3a}
*{box-sizing:border-box}
html{font-size:18px}
body{margin:0;background:var(--paper);color:var(--ink);font-family:Georgia,"Times New Roman",serif;line-height:1.55}
.wrap{max-width:960px;margin:0 auto;padding:0 16px}
main.wrap{padding-top:20px;padding-bottom:40px;outline:none}
.skip{position:absolute;left:-999px;top:0;background:#fff;padding:8px;z-index:50}.skip:focus{left:8px}
.top{background:var(--navy);color:#fff;border-bottom:5px solid var(--gold);position:sticky;top:0;z-index:20}
.top .wrap{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:56px;flex-wrap:wrap}
.brand{color:#fff;text-decoration:none;font-weight:700;font-size:1.05rem;font-family:Arial,Helvetica,sans-serif}
.brand span{display:block;font-weight:400;font-size:.8rem;color:var(--cyan)}
.timerbox{font:700 1.3rem Arial,sans-serif;background:#fff;color:var(--navy);padding:4px 12px;border-radius:6px;border:2px solid var(--gold)}
.timerbox.low{background:#fff3c4;color:var(--bad)}
h1,h2,h3{font-family:Arial,Helvetica,sans-serif;color:var(--navy);line-height:1.25}
h1{font-size:1.7rem;border-bottom:4px solid var(--teal);padding-bottom:6px}
h2{font-size:1.3rem;margin-top:1.8em}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px;padding:0;list-style:none}
.card{background:#fff;border:2px solid var(--line);border-left:8px solid var(--teal);border-radius:8px;padding:14px}
.card h3{margin:0 0 6px;font-size:1.1rem}
.card p{margin:0 0 10px;font-size:.9rem}
.btn,button{font:700 1rem Arial,sans-serif;min-height:44px;padding:8px 16px;border-radius:6px;border:2px solid var(--navy);background:var(--navy);color:#fff;cursor:pointer;text-decoration:none;display:inline-block}
.btn.alt,button.alt{background:#fff;color:var(--navy)}
.btn.gold,button.gold{background:var(--gold);color:#10213f;border-color:#8a6f1f}
button:disabled{opacity:.5;cursor:not-allowed}
:focus-visible{outline:3px solid #b45f00;outline-offset:2px}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.small{font-size:.85rem}
.q{background:#fff;border:2px solid var(--line);border-radius:10px;padding:16px;margin:14px 0}
.q .meta{font:700 .85rem Arial,sans-serif;color:var(--teal);margin-bottom:6px}
.stem{font-size:1.08rem;margin:0 0 12px}
.opts{list-style:none;padding:0;margin:0}
.opt{display:flex;gap:10px;align-items:flex-start;border:2px solid var(--line);border-radius:8px;padding:10px 12px;margin:8px 0;background:#fff;cursor:pointer}
.opt input{margin-top:.45em;width:20px;height:20px;flex:none}
.opt.sel{border-color:var(--navy);background:#e1f3f5}
.opt.right{border-color:var(--good);background:#e4f6ea}
.opt.wrong{border-color:var(--bad);background:#fbe9e9}
.opt b{font-family:Arial,sans-serif;color:var(--navy)}
.fig{margin:0 0 12px;text-align:center}
.fig img{max-width:100%;height:auto;border:1px solid var(--line);cursor:zoom-in;background:#fff}
.nav{display:flex;flex-wrap:wrap;gap:6px;margin:12px 0}
.nav button{min-width:44px;padding:4px 6px;background:#fff;color:var(--navy);border-color:var(--line);font-size:.9rem;position:relative}
.nav button.ans{background:var(--teal);color:#fff;border-color:var(--teal)}
.nav button.cur{outline:3px solid var(--gold)}
.nav button.flag::after{content:"";position:absolute;top:2px;right:2px;border:5px solid var(--gold);border-left-color:transparent;border-bottom-color:transparent}
.nav button.right{background:var(--good);color:#fff;border-color:var(--good)}
.nav button.wrong{background:var(--bad);color:#fff;border-color:var(--bad)}
.expl{border-left:6px solid var(--gold);background:#fffaf0;padding:10px 14px;margin:12px 0;border-radius:4px}
.expl h4{margin:0 0 4px;font-family:Arial,sans-serif;color:var(--navy)}
.opt-ex{margin:6px 0;padding-left:8px}
.score{font:700 3rem Arial,sans-serif;color:var(--navy)}
table{border-collapse:collapse;width:100%;background:#fff;font-size:.95rem}
th{background:var(--navy);color:#fff;text-align:left}
th,td{padding:8px;border:1px solid var(--line)}
tbody tr:nth-child(even){background:#f3fafb}
.bar{height:10px;background:#d6e6e8;border-radius:5px;overflow:hidden;min-width:80px}.bar i{display:block;height:100%;background:var(--teal)}
.flip{perspective:900px;min-height:180px}
.flipcard{width:100%;min-height:180px;font:700 1.2rem Georgia,serif;background:#fff;color:var(--ink);border:3px solid var(--teal);border-radius:12px;padding:20px;white-space:normal}
.flipcard.back{background:var(--navy);color:#fff;border-color:var(--gold)}
.cardlist dt{font-weight:700;font-family:Arial,sans-serif;color:var(--navy);margin-top:10px}
.cardlist dd{margin:0 0 6px}
.lightbox{position:fixed;inset:0;background:rgba(14,42,92,.92);z-index:100;display:flex;flex-direction:column;align-items:center;gap:10px;padding:12px;overflow:auto}
.lightbox[hidden]{display:none}
.lightbox img{max-width:100%;background:#fff}
.foot{background:var(--navy);color:#fff;padding:14px 0;font-size:.82rem;border-top:5px solid var(--gold)}
select{font:1rem Arial,sans-serif;min-height:44px;padding:6px;border:2px solid var(--navy);border-radius:6px;background:#fff;color:var(--ink);max-width:100%}
.note{background:#fff;border:2px dashed var(--teal);padding:10px 14px;border-radius:8px}
@media(min-width:700px){html{font-size:19px}}
@media(prefers-reduced-motion:no-preference){.opt{transition:background .15s}}