:root{--bg:#f6f8fb;--card:#fff;--text:#172033;--muted:#5c667a;--line:#d8deea;--blue:#2458b8;--light:#eef3fb;--ok:#157244;--warn:#9a6100}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text);line-height:1.5}
.wrap{max-width:920px;margin:0 auto;padding:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px;margin:14px 0;box-shadow:0 4px 16px rgba(0,0,0,.04)}
h1,h2,h3{line-height:1.25} .small{font-size:14px;color:var(--muted)} .big{font-size:24px}
button,a.btn{display:inline-block;border:0;border-radius:12px;padding:12px 16px;margin:5px 6px 5px 0;font-size:16px;cursor:pointer;text-decoration:none;background:var(--blue);color:#fff}
button.secondary,a.secondary{background:#e8eef8;color:#17376f}
button.light,a.light{background:#eef2f7;color:#1d2b44}
button.danger{background:#922f2f}
button:disabled{opacity:.45;cursor:not-allowed}
input{font-size:18px;padding:12px;border:1px solid #b8c0cf;border-radius:10px;width:100%;max-width:420px}
.choice{display:block;width:100%;text-align:left;background:#fff;color:#172033;border:2px solid #cfd6e3;margin:10px 0;padding:14px;border-radius:12px}
.choice.selected{border-color:var(--blue);background:#edf3ff}
.progress{height:12px;background:#e3e7ef;border-radius:10px;overflow:hidden}.progress>div{height:100%;background:var(--blue)}
.qtext{font-size:24px;font-weight:700;margin:14px 0}
.hint{background:#fff8dc;border:1px solid #e7d385;border-radius:10px;padding:12px;margin:10px 0;display:none}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:10px}
.gradebox{border:1px solid var(--line);border-radius:12px;padding:12px;background:#fff}
.ok{color:var(--ok);font-weight:700}.warn{color:var(--warn);font-weight:700}
table{border-collapse:collapse;width:100%;font-size:14px}th,td{border:1px solid #d6dce7;padding:8px;text-align:left;vertical-align:top}
.notice{border-left:4px solid var(--blue);padding:10px 12px;background:#f2f6ff;border-radius:8px}
@media(max-width:600px){.wrap{padding:10px}.card{padding:14px}.qtext{font-size:21px}button,a.btn{width:100%;margin:5px 0}table{font-size:12px}}
@media print{button,.no-print{display:none!important}body{background:#fff}.card{box-shadow:none}}

/* English-to-English word help */
.word-help{border-bottom:2px dotted #6287aa;cursor:help;border-radius:3px;padding:0 1px}
.word-help:hover,.word-help:focus{background:#fff2b8;outline:none}
.word-help-popup{position:fixed;z-index:9999;background:#fffdf4;border:2px solid #c5a747;border-radius:12px;box-shadow:0 10px 28px rgba(0,0,0,.18);padding:10px 12px;font-size:15px;max-width:320px}
.word-help-title{font-size:19px;font-weight:800;margin-bottom:4px}
.word-help-popup.hidden{display:none}
.word-help-note{font-size:14px;color:#5c667a;margin:10px 0}