:root { --b: #1f4e9c; --b3: #eaf0fa; --k: #222; --r: #c0392b; --g: #1e8449; --bg: #f6f8fc; --card: #fff; --line: #cfd8e6; }
@media (prefers-color-scheme: dark) {
  :root { --b: #7aa7f0; --b3: #1b2840; --k: #eceff4; --r: #ff8a80; --g: #7ddc9a; --bg: #10151f; --card: #18202e; --line: #34405a; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--k); font-family: "BIZ UDPGothic", "Hiragino Maru Gothic ProN", "Meiryo", sans-serif; font-size: 17px; line-height: 1.7; }
main { max-width: 720px; margin: 0 auto; padding: 16px 16px 60px; }
header.top { background: var(--b); color: #fff; padding: 14px 16px; }
header.top .book { font-size: 13px; opacity: .85; }
header.top h1 { margin: 0; font-size: 21px; font-weight: bold; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin: 14px 0; }
.lead { font-size: 15px; }
label.f { display: block; font-weight: bold; margin-bottom: 6px; }
input[type=text], input[type=password], input[type=date], select { font-size: 20px; padding: 8px 10px; border: 2px solid var(--line); border-radius: 8px; width: 100%; background: var(--card); color: var(--k); }
input:focus, select:focus { outline: none; border-color: var(--b); }
button { font-size: 18px; font-weight: bold; padding: 12px 20px; border: none; border-radius: 10px; background: var(--b); color: #fff; cursor: pointer; }
button.sub { background: var(--b3); color: var(--b); border: 2px solid var(--b); }
button:disabled { opacity: .5; }
.q { position: relative; }
.q .n { display: inline-block; min-width: 2em; background: var(--b); color: #fff; border-radius: 6px; text-align: center; font-weight: bold; margin-right: 6px; }
.q .text { margin: 6px 0 10px; }
.q .fig { text-align: center; margin: 6px 0; }
.q .fig svg { max-width: 100%; height: auto; }
.q .row { display: flex; align-items: center; gap: 8px; }
.q .row input { flex: 1; }
.q .unit { font-size: 18px; white-space: nowrap; }
.ch { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.ch label { display: flex; gap: 6px; align-items: flex-start; border: 2px solid var(--line); border-radius: 8px; padding: 8px 10px; cursor: pointer; }
.ch input { margin-top: 6px; }
.ch label:has(input:checked) { border-color: var(--b); background: var(--b3); }
@media (max-width: 420px) { .ch { grid-template-columns: 1fr; } }
.mk { position: absolute; top: 6px; right: 12px; font-size: 30px; font-weight: bold; }
.mk.o { color: var(--g); } .mk.x { color: var(--r); }
.ans { margin-top: 6px; color: var(--g); font-weight: bold; }
.result { text-align: center; }
.result .score { font-size: 44px; font-weight: bold; color: var(--b); }
.result .judge { font-size: 30px; font-weight: bold; margin: 4px 0; }
.result .judge.ss, .result .judge.s { color: var(--g); }
.result .judge.ng { color: var(--r); font-size: 24px; }
.result .msg { font-size: 19px; font-weight: bold; margin: 8px 0; }
.err { color: var(--r); font-weight: bold; }
.btns { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-top: 12px; }
table.list { border-collapse: collapse; width: 100%; font-size: 14px; }
table.list th, table.list td { border: 1px solid var(--line); padding: 4px 6px; text-align: center; white-space: nowrap; }
table.list th { background: var(--b3); }
.scroll { overflow-x: auto; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; align-items: end; }
.hidden { display: none !important; }