/* ===== 24 点速算挑战 ===== */
#g24App .g24-hero { text-align: center; padding: 12px 10px 0; }
#g24App .g24-hero h1 { font-size: 30px; font-weight: 800; color: var(--c-text); margin-bottom: 10px; }
#g24App .g24-hero p { font-size: 15px; color: var(--c-text-sub); line-height: 1.7; }

#g24App .g24-bar { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin: 18px 0; }
#g24App .g24-diff {
    border: 2px solid var(--c-primary); background: transparent; color: var(--c-primary);
    border-radius: 999px; padding: 9px 18px; font-size: 14px; font-weight: 700;
    cursor: pointer; transition: background .15s, color .15s;
}
#g24App .g24-diff.is-on { background: var(--c-primary); color: #fff; }

#g24App .g24-panel {
    max-width: 720px; margin: 0 auto; background: var(--c-surface);
    border: 1px solid var(--c-border); border-radius: var(--radius-md);
    padding: 20px; box-shadow: var(--shadow-md);
}
#g24App .g24-head {
    display: flex; align-items: center; justify-content: space-between;
    gap: 10px; flex-wrap: wrap; margin-bottom: 16px;
}
#g24App .g24-title { font-size: 17px; font-weight: 800; color: var(--c-text); }
#g24App .g24-timer {
    font-size: 15px; font-weight: 800; color: var(--c-primary);
    background: var(--c-primary-soft); border-radius: 999px; padding: 6px 14px;
}

/* 牌 */
#g24App .g24-cards { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; min-height: 96px; }
#g24App .g24-card {
    width: 76px; height: 100px; border-radius: 12px; border: 2px solid var(--c-border);
    background: var(--c-surface-soft); color: var(--c-text);
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    font-size: 30px; font-weight: 800; cursor: pointer; transition: .15s;
    box-shadow: var(--shadow-md); user-select: none;
}
#g24App .g24-card small { font-size: 11px; font-weight: 600; color: var(--c-text-muted); margin-top: 4px; }
#g24App .g24-card:hover { transform: translateY(-2px); }
#g24App .g24-card.is-sel { border-color: var(--c-primary); background: var(--c-primary-soft); color: var(--c-primary); }
#g24App .g24-card.is-win { border-color: var(--c-accent-green); background: var(--c-primary-soft); color: var(--c-primary); }
#g24App .g24-card.is-new { animation: g24pop .32s ease; }
@keyframes g24pop { from { transform: scale(.6); opacity: 0; } to { transform: scale(1); opacity: 1; } }

/* 运算符 */
#g24App .g24-ops { display: flex; gap: 10px; justify-content: center; margin-top: 18px; flex-wrap: wrap; }
#g24App .g24-op {
    width: 56px; height: 56px; border-radius: 16px; border: 2px solid var(--c-border);
    background: var(--c-surface-soft); color: var(--c-text);
    font-size: 26px; font-weight: 800; cursor: pointer; transition: .15s;
}
#g24App .g24-op:hover { border-color: var(--c-primary); color: var(--c-primary); }
#g24App .g24-op:disabled { opacity: .45; cursor: default; }

#g24App .g24-tip {
    text-align: center; font-size: 13px; color: var(--c-text-muted);
    line-height: 1.8; margin-top: 14px;
}
#g24App .g24-msg {
    text-align: center; font-size: 16px; font-weight: 800; min-height: 24px;
    margin-top: 12px; color: var(--c-text);
}
#g24App .g24-msg.ok { color: var(--c-primary); }
#g24App .g24-msg.bad { color: var(--c-danger, #e03131); }

#g24App .g24-ctrl { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 18px; }
#g24App .g24-btn {
    border: none; border-radius: 999px; padding: 11px 18px; font-size: 14px; font-weight: 700;
    color: #fff; cursor: pointer; background: linear-gradient(135deg, var(--c-primary), var(--c-accent-cyan));
    box-shadow: var(--shadow-md);
}
#g24App .g24-btn.gray { background: var(--c-surface-2); color: var(--c-text); box-shadow: none; border: 1px solid var(--c-border); }
#g24App .g24-btn:disabled { opacity: .5; cursor: default; }

#g24App .g24-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; max-width: 720px; margin: 18px auto 0; }
#g24App .g24-box {
    background: var(--c-surface); border: 1px solid var(--c-border);
    border-radius: var(--radius-md); padding: 16px 18px; box-shadow: var(--shadow-md);
}
#g24App .g24-box h3 { font-size: 15px; font-weight: 800; color: var(--c-text); margin-bottom: 10px; }
#g24App .g24-steps { font-size: 14px; line-height: 1.95; color: var(--c-text-sub); max-height: 170px; overflow-y: auto; }
#g24App .g24-stat { font-size: 14px; line-height: 1.95; color: var(--c-text-sub); }
#g24App .g24-stat b { color: var(--c-primary); font-size: 17px; }

#g24App .g24-ai { max-width: 720px; margin: 30px auto 0; }
#g24App .g24-ai h2 { font-size: 20px; font-weight: 800; color: var(--c-text); margin-bottom: 8px; }
#g24App .g24-ai p { font-size: 14px; color: var(--c-text-sub); line-height: 1.8; margin-bottom: 14px; }
#g24App .g24-ai-row { display: flex; gap: 10px; flex-wrap: wrap; }
#g24App .g24-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;
}

#g24App .g24-info { max-width: 720px; margin: 30px auto 0; }
#g24App .g24-info h2 { font-size: 20px; font-weight: 800; color: var(--c-text); margin-bottom: 10px; }
#g24App .g24-info ul { list-style: disc; padding-left: 22px; margin-bottom: 24px; }
#g24App .g24-info li { font-size: 14px; line-height: 1.9; color: var(--c-text-sub); margin-bottom: 8px; }
#g24App .g24-info li b { color: var(--c-text); }

@media (max-width: 560px) {
    #g24App .g24-row { grid-template-columns: 1fr; }
    #g24App .g24-hero h1 { font-size: 24px; }
    #g24App .g24-card { width: 64px; height: 86px; font-size: 26px; }
}