:root {
    --bg: #0f172a;
    /* slate-900 */
    --card: #111827;
    /* gray-900 */
    --text: #e5e7eb;
    /* gray-200 */
    --muted: #a5b4fc;
    /* indigo-300 */
    --accent: #60a5fa;
    /* blue-400 */
    --ok: #10b981;
    /* emerald-500 */
    --ng: #ef4444;
    /* red-500 */
    --ring: rgba(96, 165, 250, 0.35);
}

* {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Noto Sans JP, "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
    background: linear-gradient(180deg, #0b1022, var(--bg));
    color: var(--text);
}

.site-header,
.site-footer {
    padding: 16px 20px;
    background: rgba(17, 24, 39, 0.7);
    backdrop-filter: blur(6px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.site-header h1 {
    margin: 0 0 4px 0;
    font-size: 1.6rem;
}

.site-header .sub {
    margin: 0;
    color: #c7d2fe;
    font-size: .95rem;
}

.container {
    max-width: 900px;
    margin: 24px auto;
    padding: 0 16px;
}

.card {
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 16px;
    padding: 18px;
    margin-bottom: 18px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.controls {
    display: flex;
    gap: 12px;
    align-items: center;
}

.controls input[type="number"] {
    width: 6rem;
    padding: 6px 8px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: transparent;
    color: var(--text);
}

.question {
    counter-increment: q;
}

.question h3::before {
    content: "Q" counter(q) " ";
}

.question p {
    margin-top: 6px;
}

.question label {
    display: block;
    padding: 10px 12px;
    margin: 8px 0;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    cursor: pointer;
}

.question label:hover {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--ring);
}

label.right {
    border-color: var(--ok);
    background: rgba(16, 185, 129, 0.1);
}

label.wrong {
    border-color: var(--ng);
    background: rgba(239, 68, 68, 0.1);
}

.explain summary {
    cursor: pointer;
    color: var(--muted);
}

.explain {
    margin-top: 8px;
}

.actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin: 24px 0;
}

.btn-primary,
.btn-ghost {
    padding: 12px 18px;
    border-radius: 12px;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
}

.btn-primary {
    background: var(--accent);
    color: #0b1022;
    border: 0;
}

.btn-primary:hover {
    filter: brightness(1.1);
}

.btn-ghost {
    background: transparent;
    color: var(--text);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-ghost:hover {
    border-color: var(--accent);
}

.result h2 {
    margin: 8px 0 0 0;
}

.result p {
    margin: 6px 0;
}

.feedback {
    color: #c7d2fe;
}

/* ===== 印刷（A4）設定 ===== */
@page {
    size: A4;
    margin: 12mm;
}

.only-print {
    display: none;
}

.no-print {
    display: block;
}
/* 横並び用の選択肢コンテナ */
.choices {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;         /* 折り返し */
  align-items: flex-start;
}

/* コンテナ内の各ラベルをカードっぽく */
.choices label {
  display: inline-flex;
  align-items: flex-start;
  gap: 8px;
  padding: 10px 12px;
  margin: 6px 0;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.08);
  cursor: pointer;
  min-width: clamp(220px, 48%, 420px);  /* 2列〜可変 */
}

/* 既存のホバー/正誤スタイルはそのまま有効 */
@media (max-width: 600px) {
  .choices { gap: 8px; }
  .choices label { min-width: 100%; }  /* スマホは1列表示 */
}

@media print {

    html,
    body {
        background: #fff !important;
        color: #000 !important;
    }

    .no-print {
        display: none !important;
    }

    .only-print {
        display: block !important;
    }

    .container {
        max-width: none;
        padding: 0;
    }

    .card {
        background: #fff;
        border: 0;
        box-shadow: none;
        padding: 0;
        margin: 0 0 10mm 0;
    }

    .question label {
        border: 1px solid #000;
        border-radius: 6px;
        padding: 6px 8px;
    }

    .question label.right,
    .question label.wrong {
        background: transparent;
        border-color: #000;
    }

    .explain,
    #result {
        display: none !important;
    }

    .print-footer {
        position: fixed;
        bottom: 6mm;
        left: 0;
        right: 0;
        text-align: center;
        font-size: 11px;
        color: #000;
    }
}