:root{
  --ink:#16222f; --muted:#5b6b7d; --line:#e2e9f1; --bg:#f6f8fb; --card:#ffffff;
  --brand:#1256c9; --brand-dark:#0c3d8f; --brand-ink:#0a2a5e; --accent:#f5a623;
  --ok:#0f7a55; --ok-bg:#e7f6ef; --warn:#9a6a00; --warn-bg:#fdf3e0; --bad:#c0392b;
  --radius:14px; --shadow:0 6px 24px rgba(18,42,84,.07); --shadow-lg:0 16px 44px rgba(10,42,94,.16);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;color:var(--ink);background:var(--bg);line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1080px;margin:0 auto;padding:0 20px}

/* header */
header.site{position:sticky;top:0;background:rgba(255,255,255,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--line);z-index:50}
.nav{display:flex;align-items:center;gap:22px;min-height:62px;flex-wrap:wrap;padding-top:6px;padding-bottom:6px}
.logo{font-weight:800;font-size:20px;color:var(--ink);letter-spacing:.2px;display:flex;align-items:center;gap:9px}
.logo:hover{text-decoration:none}
.logo .mark{display:inline-flex;align-items:center;justify-content:center;width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,var(--brand) 0%,var(--brand-ink) 100%);color:#fff;font-size:15px;font-weight:800}
.logo span{color:var(--brand)}
.nav nav{display:flex;gap:18px;margin-left:auto;font-size:15px;flex-wrap:wrap}
.nav nav a{color:var(--ink);padding:4px 2px;border-bottom:2px solid transparent}
.nav nav a:hover{color:var(--brand);text-decoration:none;border-bottom-color:var(--brand)}
.btn{display:inline-block;background:var(--brand);color:#fff!important;padding:11px 22px;border-radius:10px;font-weight:600;border:0;cursor:pointer;font-size:15px;box-shadow:0 4px 14px rgba(18,86,201,.25);transition:background .15s,transform .15s}
.btn:hover{background:var(--brand-dark);text-decoration:none;transform:translateY(-1px)}
.btn.ghost{background:#fff;color:var(--brand)!important;border:1px solid var(--brand);box-shadow:none}
.btn.ghost:hover{background:#eef3fb}
.btn.small{padding:7px 14px;font-size:14px}
.btn:disabled{opacity:.45;cursor:default;transform:none}

/* hero */
.hero{padding:72px 0 56px;background:radial-gradient(900px 420px at 85% -60px,rgba(245,166,35,.20),transparent 60%),linear-gradient(160deg,#0a2a5e 0%,#0d3f96 52%,#1256c9 100%);color:#eaf1fd}
.hero h1{font-size:42px;line-height:1.18;max-width:780px;color:#fff;letter-spacing:-.2px}
.hero h1 em{font-style:normal;color:#ffc95e}
.hero p.lead{margin-top:18px;font-size:18px;color:#c9d9f6;max-width:700px}
.hero .cta{margin-top:28px;display:flex;gap:12px;flex-wrap:wrap}
.hero .btn{background:#fff;color:var(--brand-ink)!important;box-shadow:0 6px 20px rgba(0,0,0,.25)}
.hero .btn:hover{background:#eaf1fd}
.hero .btn.ghost{background:transparent;color:#fff!important;border:1px solid rgba(255,255,255,.65);box-shadow:none}
.hero .btn.ghost:hover{background:rgba(255,255,255,.12)}
.badge{display:inline-block;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.35);border-radius:999px;padding:4px 13px;font-size:13px;color:#eaf1fd;margin-bottom:18px}
.stat-strip{display:flex;gap:14px;flex-wrap:wrap;margin-top:30px}
.stat{background:rgba(255,255,255,.10);border:1px solid rgba(255,255,255,.22);border-radius:12px;padding:11px 17px;font-size:14px;color:#dbe7fb}
.stat b{font-size:17px;color:#fff}

/* sections & cards */
section{padding:48px 0}
section.alt{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
h2{font-size:28px;margin-bottom:8px;letter-spacing:-.2px}
.sub{color:var(--muted);margin-bottom:28px;max-width:740px}
.grid{display:grid;gap:18px}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.grid.c2{grid-template-columns:repeat(2,1fr)}
@media(max-width:820px){.grid.c3,.grid.c2{grid-template-columns:1fr}.hero h1{font-size:32px}.hero{padding:52px 0 42px}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.card h3{font-size:18px;margin-bottom:6px}
.card p{color:var(--muted);font-size:15px}
.tag{display:inline-block;font-size:12px;background:#eef3fb;color:var(--brand-dark);border-radius:6px;padding:2px 9px;margin-bottom:10px;font-weight:700;letter-spacing:.4px}
.step-num{display:inline-flex;align-items:center;justify-content:center;width:30px;height:30px;border-radius:50%;background:var(--brand);color:#fff;font-weight:800;font-size:15px;margin-bottom:12px}

/* tables */
table{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
th,td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--line);font-size:15px;vertical-align:top}
th{background:#eef3fb;font-size:13.5px;letter-spacing:.3px;text-transform:uppercase;color:var(--brand-ink)}
tr:last-child td{border-bottom:0}
tbody tr:hover td{background:#f8fbff}

/* status pills */
.pill{display:inline-block;font-size:12.5px;font-weight:700;border-radius:999px;padding:2.5px 11px;white-space:nowrap}
.pill.live{background:var(--ok-bg);color:var(--ok)}
.pill.soon{background:var(--warn-bg);color:var(--warn)}
.pill.plan{background:#eef3fb;color:var(--brand-dark)}

/* sample question */
.sample-q{background:#fff;border:1px solid var(--line);border-left:5px solid var(--brand);border-radius:var(--radius);padding:24px 26px;box-shadow:var(--shadow)}
.sample-q .qstem{font-size:18px;font-weight:600}
.sample-q .opts-static{display:grid;gap:8px;margin:14px 0}
.sample-q .opt-static{border:1px solid var(--line);border-radius:10px;padding:10px 15px;font-size:15.5px;background:#fbfcfe}
.sample-q .opt-static.right{border-color:var(--ok);background:var(--ok-bg);font-weight:600}
.sample-q .explain-static{border-top:1px dashed var(--line);padding-top:12px;font-size:15px;color:#33404f}
.sample-q .trap{background:#fff7e8;border:1px solid #f3ddae;border-radius:8px;padding:9px 13px;font-size:14px;margin-top:10px}

/* checklist */
.checklist{list-style:none}
.checklist li{padding:7px 0 7px 30px;position:relative;font-size:15.5px}
.checklist li::before{content:"✓";position:absolute;left:2px;color:var(--ok);font-weight:800}
.crosslist{list-style:none}
.crosslist li{padding:7px 0 7px 30px;position:relative;font-size:15.5px;color:var(--muted)}
.crosslist li::before{content:"✕";position:absolute;left:2px;color:var(--bad);font-weight:800}

/* pricing */
.price-card{text-align:left;position:relative;display:flex;flex-direction:column}
.price-card .price{font-size:36px;font-weight:800;margin:8px 0 2px}
.price-card .per{color:var(--muted);font-size:14px}
.price-card ul{list-style:none;margin:14px 0 20px}
.price-card li{padding:5px 0 5px 24px;position:relative;font-size:15px}
.price-card li::before{content:"✓";position:absolute;left:0;color:var(--ok);font-weight:700}
.price-card .btn{margin-top:auto;text-align:center}
.price-card.featured{border:2px solid var(--brand);box-shadow:var(--shadow-lg)}
.price-card .ribbon{position:absolute;top:-13px;right:18px;background:var(--accent);color:#3a2a00;font-size:12px;font-weight:700;padding:3px 11px;border-radius:999px;box-shadow:0 4px 10px rgba(245,166,35,.4)}

/* faq */
.faq details{background:#fff;border:1px solid var(--line);border-radius:10px;padding:15px 19px;margin-bottom:10px;box-shadow:var(--shadow)}
.faq summary{font-weight:600;cursor:pointer}
.faq p{color:var(--muted);margin-top:8px;font-size:15px}

/* footer */
footer.site{border-top:1px solid #22314a;background:#131f31;color:#b9c7da;padding:40px 0 34px;margin-top:24px}
footer .cols{display:flex;gap:44px;flex-wrap:wrap;font-size:14px}
footer h4{font-size:14px;margin-bottom:9px;color:#fff}
footer ul{list-style:none}
footer li{margin:5px 0}
footer a{color:#b9c7da}
footer a:hover{color:#fff}
.support-line{margin-top:22px;background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.14);border-radius:10px;padding:12px 16px;font-size:14px;color:#dbe7fb}
.support-line a{color:#ffc95e;font-weight:600}
.disclaimer{margin-top:20px;font-size:13px;color:#8fa3bd;border-top:1px solid rgba(255,255,255,.12);padding-top:16px}

/* legal pages */
.legal{max-width:820px}
.legal h1{font-size:31px;margin:38px 0 6px}
.legal h2{font-size:20px;margin:28px 0 6px}
.legal p,.legal li{color:#33404f;font-size:15.5px}
.legal ul{margin:6px 0 6px 22px}
.legal .updated{color:var(--muted);font-size:14px;margin-bottom:10px}
.callout{background:#eef3fb;border:1px solid #cfddf5;border-radius:10px;padding:14px 18px;margin:16px 0;font-size:15px;color:#22354d}

/* practice app */
.app-shell{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
.modebar{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:18px}
.modebar button{padding:9px 17px;border-radius:999px;border:1px solid var(--line);background:#fff;cursor:pointer;font-size:14px;font-weight:600;transition:all .15s}
.modebar button:hover{border-color:var(--brand);color:var(--brand)}
.modebar button.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.qmeta{display:flex;gap:10px;align-items:center;font-size:13px;color:var(--muted);margin-bottom:8px;flex-wrap:wrap}
.qmeta .kp{background:#eef3fb;color:var(--brand-dark);padding:2px 9px;border-radius:6px;font-weight:600}
.qstem{font-size:18px;font-weight:600;margin-bottom:4px}
.qstem-zh{font-size:15px;color:var(--muted);margin-bottom:16px}
.opts{display:grid;gap:10px}
.opt{border:1px solid var(--line);border-radius:10px;padding:12px 16px;cursor:pointer;font-size:16px;background:#fff;text-align:left;width:100%;transition:border-color .12s,background .12s}
.opt:hover{border-color:var(--brand)}
.opt.sel{border-color:var(--brand);background:#eef3fb}
.opt.right{border-color:var(--ok);background:var(--ok-bg)}
.opt.wrong{border-color:var(--bad);background:#fdecea}
.explain{margin-top:16px;border-top:1px dashed var(--line);padding-top:14px;display:none}
.explain.show{display:block}
.explain .verdict{font-weight:700;margin-bottom:6px}
.explain .verdict.ok{color:var(--ok)} .explain .verdict.bad{color:var(--bad)}
.explain p{font-size:15px;color:#33404f;margin-bottom:6px}
.explain .vi{color:var(--muted)}
.explain .trap{background:#fff7e8;border:1px solid #f3ddae;border-radius:8px;padding:8px 12px;font-size:14px}
.appnav{display:flex;gap:10px;margin-top:20px;flex-wrap:wrap}
.timer{font-weight:700;font-variant-numeric:tabular-nums}
.scorebox{text-align:center;padding:18px 0}
.scorebox .big{font-size:46px;font-weight:800}
.kp-row{display:flex;justify-content:space-between;border-bottom:1px solid var(--line);padding:8px 2px;font-size:15px}
.note{font-size:13.5px;color:var(--muted)}