/* ===== 图形推理练习 ===== */
#mrApp .mr-hero { text-align: center; padding: 12px 10px 0; }
#mrApp .mr-hero h1 { font-size: 30px; font-weight: 800; color: var(--c-text); margin-bottom: 10px; }
#mrApp .mr-hero p { font-size: 15px; color: var(--c-text-sub); line-height: 1.7; }

#mrApp .mr-bar { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin: 18px 0; }
#mrApp .mr-tab {
    border: 2px solid var(--c-primary); background: transparent; color: var(--c-primary);
    border-radius: 999px; padding: 8px 16px; font-size: 14px; font-weight: 700;
    cursor: pointer; transition: background .15s, color .15s;
}
#mrApp .mr-tab.is-on { background: var(--c-primary); color: #fff; }

#mrApp .mr-panel {
    max-width: 680px; margin: 0 auto; background: var(--c-surface);
    border: 1px solid var(--c-border); border-radius: var(--radius-md);
    padding: 22px 18px; box-shadow: var(--shadow-md); text-align: center;
}
#mrApp .mr-q { font-size: 18px; font-weight: 800; color: var(--c-text); margin-bottom: 16px; }

#mrApp .mr-matrix { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; max-width: 420px; margin: 0 auto; }
#mrApp .mr-cell {
    aspect-ratio: 1 / 1; border: 2px solid var(--c-border); border-radius: 14px;
    background: var(--c-surface-soft); display: flex; align-items: center; justify-content: center;
    padding: 6px;
}
#mrApp .mr-cell svg { width: 100%; height: 100%; display: block; }
#mrApp .mr-cell.blank { border-style: dashed; border-color: var(--c-primary); background: var(--c-primary-soft); }
#mrApp .mr-cell .q { font-size: 34px; font-weight: 900; color: var(--c-primary); }

#mrApp .mr-opts { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-top: 20px; }
#mrApp .mr-opt {
    aspect-ratio: 1 / 1; border: 2px solid var(--c-border); border-radius: 14px;
    background: var(--c-surface-soft); cursor: pointer; padding: 6px; transition: .15s;
    display: flex; align-items: center; justify-content: center;
}
#mrApp .mr-opt svg { width: 100%; height: 100%; display: block; }
#mrApp .mr-opt:hover { border-color: var(--c-primary); }
#mrApp .mr-opt.ok { border-color: var(--c-accent-green); background: var(--c-primary-soft); box-shadow: 0 0 0 3px rgba(74,163,137,.18); }
#mrApp .mr-opt.bad { border-color: #e03131; background: #fff0f0; }

#mrApp .mr-rule {
    display: none; margin-top: 18px; text-align: left; background: var(--c-primary-soft);
    border: 1px solid var(--c-border); border-radius: var(--radius-sm); padding: 14px 16px;
    font-size: 14px; line-height: 1.9; color: var(--c-text);
}
#mrApp .mr-rule.show { display: block; }
#mrApp .mr-rule b { color: var(--c-primary); }

#mrApp .mr-msg { font-size: 17px; font-weight: 800; min-height: 26px; margin-top: 16px; color: var(--c-text); }
#mrApp .mr-msg.ok { color: var(--c-primary); }
#mrApp .mr-msg.bad { color: #e03131; }

#mrApp .mr-stat {
    max-width: 680px; margin: 18px auto 0; background: var(--c-surface);
    border: 1px solid var(--c-border); border-radius: var(--radius-md);
    padding: 14px 18px; box-shadow: var(--shadow-md); text-align: center;
    font-size: 14px; line-height: 1.9; color: var(--c-text-sub);
}
#mrApp .mr-stat b { color: var(--c-primary); font-size: 17px; }

#mrApp .mr-ctrl { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 18px; }
#mrApp .mr-btn {
    border: none; border-radius: 999px; padding: 12px 20px; font-size: 15px; font-weight: 700;
    color: #fff; cursor: pointer; background: linear-gradient(135deg, var(--c-primary), var(--c-accent-cyan));
    box-shadow: var(--shadow-md);
}
#mrApp .mr-btn.gray { background: var(--c-surface-2); color: var(--c-text); box-shadow: none; border: 1px solid var(--c-border); }

#mrApp .mr-ai, #mrApp .mr-info { max-width: 720px; margin: 30px auto 0; }
#mrApp .mr-ai h2, #mrApp .mr-info h2 { font-size: 20px; font-weight: 800; color: var(--c-text); margin-bottom: 10px; }
#mrApp .mr-ai p { font-size: 14px; color: var(--c-text-sub); line-height: 1.8; margin-bottom: 14px; }
#mrApp .mr-ai-row { display: flex; gap: 10px; flex-wrap: wrap; }
#mrApp .mr-out {
    margin-top: 14px; background: var(--c-surface-soft); border: 1px solid var(--c-border);
    border-radius: var(--radius-sm); padding: 16px 18px;
    font-size: 15px; line-height: 1.85; color: var(--c-text); white-space: pre-wrap;
}
#mrApp .mr-info ul { list-style: disc; padding-left: 22px; margin-bottom: 24px; }
#mrApp .mr-info li { font-size: 14px; line-height: 1.9; color: var(--c-text-sub); margin-bottom: 8px; }
#mrApp .mr-info li b { color: var(--c-text); }

@media (max-width: 560px) {
    #mrApp .mr-hero h1 { font-size: 24px; }
    #mrApp .mr-opts { grid-template-columns: repeat(2, 1fr); }
}