/* ======================================================================
 *  第 12 批 · 儿童数学工具组 共享皮肤（kids-math.css）
 *  风格：数学乐园 —— 方格练习本底纹 + 糖果色圆角卡 + 立体按压按钮
 *  覆盖：头部 / 工具台 / 题卡纸 / 答案卷 / 打印与答案分离 / 深色模式
 *  说明：所有颜色走 var(--c-*)，深色模式由 theme-toggle.css 自动接管；
 *        每页用 style="--km-accent:#xxx" 指定自己的强调色。
 * ====================================================================== */

.km {
    --km-accent: #f97316;
    --km-accent-2: #fbbf24;
    --km-accent-soft: color-mix(in srgb, var(--km-accent) 12%, transparent);
    --km-radius: 16px;
    --km-paper-bg: #fffdf7;
    --km-paper-line: rgba(148, 163, 184, .28);
    color: var(--c-text);
}

:root[data-theme="dark"] .km {
    --km-paper-bg: #161f33;
    --km-paper-line: rgba(148, 163, 184, .16);
    --km-accent-soft: color-mix(in srgb, var(--km-accent) 22%, transparent);
}

/* 主题色变体（在不同工具页营造差异） */
.km-t1 { --km-accent: #f97316; --km-accent-2: #fbbf24; }
.km-t2 { --km-accent: #2563eb; --km-accent-2: #38bdf8; }
.km-t3 { --km-accent: #16a34a; --km-accent-2: #84cc16; }
.km-t4 { --km-accent: #7c3aed; --km-accent-2: #c084fc; }
.km-t5 { --km-accent: #db2777; --km-accent-2: #fb7185; }
.km-t6 { --km-accent: #0891b2; --km-accent-2: #22d3ee; }

/* ---------------- 头部 ---------------- */
.km-head {
    display: flex; align-items: flex-start; gap: 18px;
    padding: 24px 26px; margin-bottom: 22px;
    border-radius: 22px;
    background:
        radial-gradient(1200px 200px at 0% 0%, var(--km-accent-soft), transparent 60%),
        var(--c-bg-card);
    border: 1px solid var(--c-border);
    position: relative; overflow: hidden;
}
.km-head::after {
    content: ""; position: absolute; right: -30px; top: -30px;
    width: 160px; height: 160px; border-radius: 50%;
    background: radial-gradient(circle, color-mix(in srgb, var(--km-accent-2) 26%, transparent), transparent 70%);
    pointer-events: none;
}
.km-head-icon {
    flex: 0 0 auto; width: 60px; height: 60px; border-radius: 18px;
    display: grid; place-items: center; font-size: 32px;
    background: linear-gradient(150deg, var(--km-accent), var(--km-accent-2));
    box-shadow: 0 8px 20px color-mix(in srgb, var(--km-accent) 34%, transparent);
}
.km-head-main { min-width: 0; }
.km-head h1 { margin: 0 0 6px; font-size: 26px; line-height: 1.25; font-weight: 800; letter-spacing: .2px; }
.km-head-sub { margin: 0 0 12px; font-size: 14.5px; line-height: 1.7; color: var(--c-text-sub); }
.km-head-badges { display: flex; flex-wrap: wrap; gap: 8px; }
.km-head-badges .badge {
    font-size: 12px; font-weight: 600; padding: 4px 11px; border-radius: 999px;
    background: var(--c-bg-soft); border: 1px solid var(--c-border); color: var(--c-text-sub);
}
.km-head-badges .b-hot {
    background: linear-gradient(120deg, var(--km-accent), var(--km-accent-2));
    color: #fff; border-color: transparent;
}

/* ---------------- 工具台 ---------------- */
.km-board {
    background: var(--c-bg-card); border: 1px solid var(--c-border);
    border-radius: var(--km-radius); padding: 20px; margin-bottom: 24px;
}
.km-toolbar { display: flex; flex-wrap: wrap; gap: 14px 18px; align-items: flex-end; }
.km-field { display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.km-field > label, .km-label { font-size: 12.5px; font-weight: 700; color: var(--c-text-sub); }
.km-select, .km-input {
    height: 40px; padding: 0 12px; border-radius: 10px; font-size: 14px;
    background: var(--c-bg-soft); border: 1px solid var(--c-border); color: var(--c-text);
    outline: none; transition: border-color .16s, box-shadow .16s; min-width: 96px;
}
.km-input[type="number"] { width: 92px; }
.km-select:focus, .km-input:focus {
    border-color: var(--km-accent);
    box-shadow: 0 0 0 3px var(--km-accent-soft);
}
.km-seg { display: inline-flex; background: var(--c-bg-soft); border: 1px solid var(--c-border); border-radius: 11px; padding: 3px; gap: 3px; }
.km-seg button {
    border: 0; background: transparent; color: var(--c-text-sub); cursor: pointer;
    font-size: 13.5px; font-weight: 600; padding: 7px 13px; border-radius: 8px; transition: all .16s;
}
.km-seg button:hover { color: var(--c-text); }
.km-seg button.active {
    background: linear-gradient(150deg, var(--km-accent), var(--km-accent-2));
    color: #fff; box-shadow: 0 3px 10px color-mix(in srgb, var(--km-accent) 32%, transparent);
}

/* ---------------- 按钮 ---------------- */
.km-btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 7px;
    height: 42px; padding: 0 20px; border-radius: 12px; border: 0; cursor: pointer;
    font-size: 14.5px; font-weight: 700; color: #fff; white-space: nowrap;
    background: linear-gradient(150deg, var(--km-accent), var(--km-accent-2));
    box-shadow: 0 4px 0 color-mix(in srgb, var(--km-accent) 62%, #000 6%);
    transition: transform .12s, box-shadow .12s, filter .16s;
}
.km-btn:hover { filter: brightness(1.04); }
.km-btn:active { transform: translateY(3px); box-shadow: 0 1px 0 color-mix(in srgb, var(--km-accent) 62%, #000 6%); }
.km-btn.ghost {
    background: var(--c-bg-soft); color: var(--c-text); border: 1px solid var(--c-border);
    box-shadow: 0 3px 0 var(--c-border);
}
.km-btn.ghost:active { box-shadow: 0 1px 0 var(--c-border); }
.km-btn.sm { height: 36px; padding: 0 14px; font-size: 13.5px; border-radius: 10px; }

/* ---------------- 选项 chip ---------------- */
.km-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.km-chip {
    font-size: 13px; font-weight: 600; padding: 6px 13px; border-radius: 999px;
    background: var(--c-bg-soft); border: 1px solid var(--c-border); color: var(--c-text-sub);
    cursor: pointer; transition: all .16s; user-select: none;
}
.km-chip:hover { border-color: var(--km-accent); color: var(--c-text); }
.km-chip.active {
    background: var(--km-accent-soft); border-color: var(--km-accent); color: var(--km-accent);
}

/* ---------------- 题卡纸 ---------------- */
.km-paper {
    margin-top: 18px; padding: 26px 28px; border-radius: 14px;
    background:
        repeating-linear-gradient(0deg, transparent 0 27px, var(--km-paper-line) 27px 28px),
        var(--km-paper-bg);
    border: 1px solid var(--c-border);
    box-shadow: 0 10px 30px rgba(16, 24, 40, .06);
}
.km-paper-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 10px; padding-bottom: 12px; border-bottom: 2px dashed var(--km-paper-line); margin-bottom: 16px; }
.km-paper-head h2 { margin: 0; font-size: 20px; font-weight: 800; }
.km-paper-meta { font-size: 13px; color: var(--c-text-sub); letter-spacing: .5px; }
.km-paper-meta b { color: var(--c-text); font-weight: 600; }

.km-q-grid { display: grid; gap: 14px 18px; }
.km-q-grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.km-q-grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.km-q-grid.cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.km-q-grid.cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.km-q {
    display: flex; align-items: baseline; gap: 6px; font-size: 16px;
    font-variant-numeric: tabular-nums; line-height: 2;
}
.km-q .no {
    flex: 0 0 auto; min-width: 22px; font-size: 12px; color: var(--c-text-muted); font-weight: 700;
}
.km-q .stem { letter-spacing: .5px; }
.km-q .blank { display: inline-block; min-width: 52px; border-bottom: 1.5px solid var(--c-text-muted); height: 1.1em; vertical-align: -2px; }

/* 答案卷 */
.km-answer-sheet { margin-top: 22px; padding-top: 16px; border-top: 2px dashed var(--km-paper-line); }
.km-answer-sheet .ans-head { font-size: 15px; font-weight: 800; margin: 0 0 10px; color: var(--km-accent); }
.km-ans-grid { display: grid; gap: 8px 16px; }
.km-ans-grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.km-ans-grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.km-ans-grid.cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.km-ans-grid.cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.km-ans { font-size: 14px; color: var(--c-text-sub); font-variant-numeric: tabular-nums; }
.km-ans b { color: var(--c-text); font-weight: 700; }
.km-ans .no { color: var(--c-text-muted); }

/* 页面内显示答案开关 */
.km-paper.show-ans .km-q .blank { border: 0; color: var(--km-accent); font-weight: 700; min-width: 0; }
.km-paper.show-ans .km-q .blank::before { content: attr(data-ans); }

/* ---------------- 打印条 ---------------- */
.km-print-bar {
    display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px;
    margin-top: 16px; padding: 14px 16px; border-radius: 12px;
    background: var(--c-bg-soft); border: 1px dashed var(--c-border);
}
.km-print-bar .km-switch { display: inline-flex; align-items: center; gap: 8px; font-size: 13.5px; color: var(--c-text-sub); cursor: pointer; }
.km-print-bar .km-switch input { width: 16px; height: 16px; accent-color: var(--km-accent); }
.km-print-bar .hint { font-size: 12.5px; color: var(--c-text-muted); }

/* ---------------- 统计 / 反馈 ---------------- */
.km-stat-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 14px; }
.km-stat {
    flex: 1 1 120px; padding: 12px 14px; border-radius: 12px; background: var(--c-bg-soft);
    border: 1px solid var(--c-border);
}
.km-stat .k { font-size: 12px; color: var(--c-text-muted); }
.km-stat .v { font-size: 20px; font-weight: 800; font-variant-numeric: tabular-nums; }
.km-stat .v.ok { color: #16a34a; }
.km-stat .v.bad { color: #dc2626; }

.km-feedback { margin-top: 12px; font-size: 14px; min-height: 20px; font-weight: 600; }
.km-feedback.ok { color: #16a34a; }
.km-feedback.bad { color: #dc2626; }

/* ---------------- 提示 ---------------- */
.km-tip {
    margin: 16px 0 0; padding: 12px 15px; border-radius: 12px; font-size: 13px; line-height: 1.75;
    background: var(--c-bg-soft); border-left: 4px solid var(--km-accent); color: var(--c-text-sub);
}
.km-tip b { color: var(--c-text); }

/* ---------------- AI ---------------- */
.km-ai { margin-top: 16px; padding: 16px; border-radius: 12px; background: var(--c-bg-soft); border: 1px solid var(--c-border); }
.km-ai-btn {
    display: inline-flex; align-items: center; gap: 8px; height: 42px; padding: 0 20px; border: 0; cursor: pointer;
    border-radius: 12px; font-size: 14.5px; font-weight: 700; color: #fff;
    background: linear-gradient(150deg, #6366f1, #a855f7);
    box-shadow: 0 4px 0 #4f46e5; transition: transform .12s, box-shadow .12s;
}
.km-ai-btn:active { transform: translateY(3px); box-shadow: 0 1px 0 #4f46e5; }
.km-ai-btn:disabled { opacity: .7; cursor: progress; }
.km-ai-status { margin-top: 10px; font-size: 13px; color: var(--c-text-muted); }
.km-ai-result {
    margin-top: 12px; padding: 15px 16px; border-radius: 12px; font-size: 14px; line-height: 1.85;
    background: var(--c-bg-card); border: 1px solid var(--c-border); color: var(--c-text);
    white-space: pre-wrap;
}
.km-ai-result .ac-ai-head { font-weight: 800; margin-bottom: 8px; color: #7c3aed; }
.km-ai-result .ac-ai-disclaim { margin-top: 10px; font-size: 12px; color: var(--c-text-muted); }

/* ---------------- Tab 内容区 ---------------- */
.km-block-head { font-size: 18px; font-weight: 800; margin: 26px 0 14px; padding-left: 12px; border-left: 4px solid var(--km-accent); }
.km-prose { font-size: 14.5px; line-height: 1.9; color: var(--c-text-sub); margin: 0 0 12px; }
.km-prose b { color: var(--c-text); }
.km-feature-chips { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 10px; }
.km-feature-chip {
    display: flex; align-items: center; gap: 9px; font-size: 13.5px; padding: 11px 14px;
    border-radius: 11px; background: var(--c-bg-soft); border: 1px solid var(--c-border); color: var(--c-text-sub);
}
.km-feature-chip .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--km-accent); flex: 0 0 auto; }

.km-steps { display: flex; flex-direction: column; gap: 12px; }
.km-step { display: flex; gap: 13px; padding: 14px 16px; border-radius: 12px; background: var(--c-bg-soft); border: 1px solid var(--c-border); }
.km-step-no {
    flex: 0 0 auto; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
    font-weight: 800; font-size: 14px; color: #fff; background: linear-gradient(150deg, var(--km-accent), var(--km-accent-2));
}
.km-step-body { font-size: 14px; line-height: 1.8; color: var(--c-text-sub); }
.km-step-body b { color: var(--c-text); }

.km-faq { display: flex; flex-direction: column; gap: 10px; }
.km-faq-item { border: 1px solid var(--c-border); border-radius: 12px; background: var(--c-bg-soft); overflow: hidden; }
.km-faq-item summary { cursor: pointer; padding: 14px 16px; font-size: 14.5px; font-weight: 700; list-style: none; }
.km-faq-item summary::-webkit-details-marker { display: none; }
.km-faq-item summary::before { content: "❓ "; }
.km-faq-item[open] summary { color: var(--km-accent); }
.km-faq-a { padding: 0 16px 15px; font-size: 14px; line-height: 1.85; color: var(--c-text-sub); }
.km-faq-a b { color: var(--c-text); }

/* ---------------- 相关工具 ---------------- */
.km-related { margin-top: 34px; }
.km-related h2 { font-size: 17px; font-weight: 800; margin: 0 0 14px; }
.km-rel-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(238px, 1fr)); gap: 12px; }
.km-rel-item {
    display: flex; align-items: center; gap: 12px; padding: 13px 15px; border-radius: 13px;
    background: var(--c-bg-card); border: 1px solid var(--c-border); text-decoration: none;
    transition: transform .16s, border-color .16s, box-shadow .16s;
}
.km-rel-item:hover { transform: translateY(-2px); border-color: var(--km-accent); box-shadow: 0 10px 24px color-mix(in srgb, var(--km-accent) 16%, transparent); }
.km-rel-icon { font-size: 24px; flex: 0 0 auto; }
.km-rel-body { display: flex; flex-direction: column; min-width: 0; }
.km-rel-body b { font-size: 14px; color: var(--c-text); }
.km-rel-body small { font-size: 12px; color: var(--c-text-muted); }
.km-rel-go { margin-left: auto; color: var(--c-text-muted); font-size: 16px; }

/* ---------------- 通用图形板（钟面 / 坐标系 / 展开图） ---------------- */
.km-canvas-row { display: flex; flex-wrap: wrap; gap: 20px; align-items: flex-start; justify-content: center; margin-top: 16px; }
.km-figure { background: var(--c-bg-card); border: 1px solid var(--c-border); border-radius: 14px; padding: 14px; }
.km-figure svg { display: block; width: 100%; height: auto; }
.km-option-btns { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 14px; }
.km-opt {
    min-width: 84px; height: 44px; padding: 0 16px; border-radius: 12px; cursor: pointer;
    font-size: 15px; font-weight: 700; font-variant-numeric: tabular-nums;
    background: var(--c-bg-soft); border: 1.5px solid var(--c-border); color: var(--c-text);
    transition: all .16s;
}
.km-opt:hover { border-color: var(--km-accent); }
.km-opt.correct { background: color-mix(in srgb, #16a34a 16%, transparent); border-color: #16a34a; color: #15803d; }
.km-opt.wrong { background: color-mix(in srgb, #dc2626 14%, transparent); border-color: #dc2626; color: #b91c1c; }
:root[data-theme="dark"] .km-opt.correct { color: #4ade80; }
:root[data-theme="dark"] .km-opt.wrong { color: #f87171; }

/* ---------------- 打印 ---------------- */
@media print {
    body { background: #fff !important; }
    .nav-header, .site-footer, .header, .detail-breadcrumb, .detail-tabs,
    .tab-panel, .km-related, .back-to-top, .theme-toggle, .km-toolbar,
    .km-print-bar, .km-tip, .km-ai, .km-head-badges, .km-stat-row, .km-feedback,
    .km-canvas-hide, .comments-wrap, .comments-section { display: none !important; }

    .detail-wrap { padding: 0 !important; }
    .container { max-width: none !important; padding: 0 !important; }
    .km-head { padding: 0 0 8px; margin: 0 0 8px; border: 0; background: none !important; border-radius: 0; }
    .km-head::after { display: none; }
    .km-head-icon { width: 40px; height: 40px; font-size: 22px; border-radius: 10px; box-shadow: none; background: none; }
    .km-head h1 { font-size: 20px; }
    .km-head-sub { font-size: 12px; color: #555; }
    .km-board { border: 0 !important; padding: 0 !important; background: none !important; }
    .km-paper {
        margin: 0 !important; padding: 0 !important; border: 0 !important; box-shadow: none !important;
        background: #fff !important; border-radius: 0;
    }
    .km-paper-head { border-bottom: 1.5px solid #333; }
    .km-paper-head h2 { color: #000; }
    .km-q, .km-ans, .km-paper-meta { color: #000 !important; }
    .km-q .no, .km-ans .no { color: #666 !important; }
    .km-ans b { color: #000 !important; }
    .km-answer-sheet { border-top: 1.5px dashed #999; }

    /* 默认印答案；只印练习卷时隐藏答案卷 */
    .km-answer-sheet { display: block !important; }
    body.km-print-q .km-answer-sheet { display: none !important; }
    body.km-print-a .km-question-sheet,
    body.km-print-a .km-paper-head { display: none !important; }
    body.km-print-both .km-answer-sheet { break-before: page; }

    /* 打印时答案永远以文字呈现（不受页面开关影响） */
    .km-paper .km-q .blank { border-bottom: 1.5px solid #999 !important; color: transparent !important; min-width: 52px !important; }
    .km-answer-sheet .km-q .blank,
    .km-paper.km-paper-answer .km-q .blank { color: #000 !important; border: 0 !important; min-width: 0 !important; }
    .km-paper .km-q .blank::before { content: none !important; }
}

/* ---------------- 响应式 ---------------- */
@media (max-width: 760px) {
    .km-head { padding: 18px; gap: 13px; }
    .km-head h1 { font-size: 21px; }
    .km-q-grid.cols-3, .km-q-grid.cols-4, .km-q-grid.cols-5 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .km-ans-grid.cols-3, .km-ans-grid.cols-4, .km-ans-grid.cols-5 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .km-paper { padding: 18px 16px; }
    .km-toolbar { gap: 12px; }
    .km-input[type="number"], .km-select { width: 100%; min-width: 0; }
    .km-field { flex: 1 1 46%; }
}