/* ==========================================================================
   童书借阅与购买对比计算器 /tool/book-borrow-vs-buy-calc
   视觉主题：绘本馆台灯 —— 馆藏绿 + 借书卡牛皮纸 + 书脊橙
   质感关键词：借书卡、打孔、书脊条纹、台灯光晕、印章
   深浅双主题：跟随导航栏 #themeToggle
   ========================================================================== */

.bbv-page {
    --bbv-green: #2e6e4e;
    --bbv-green-2: #3f8a64;
    --bbv-green-soft: #e3f1e9;
    --bbv-kraft: #f5efe3;
    --bbv-kraft-2: #fdfaf3;
    --bbv-amber: #d97a29;
    --bbv-amber-deep: #a3581a;
    --bbv-amber-soft: #fbeadb;
    --bbv-ink: #2c3230;
    --bbv-ink-2: #5c6560;
    --bbv-ink-3: #8e978f;
    --bbv-line: #ddd5c4;
    --bbv-line-2: #ebe4d4;
    --bbv-red: #b64433;
    --bbv-red-soft: #f9e7e3;
    --bbv-shadow: 0 18px 40px rgba(44, 50, 48, .10);
    --bbv-shadow-sm: 0 6px 16px rgba(44, 50, 48, .07);
    --bbv-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

:root[data-theme="dark"] .bbv-page {
    --bbv-green: #6cc79a;
    --bbv-green-2: #8fd8b3;
    --bbv-green-soft: #0f2a1d;
    --bbv-kraft: #1a1f1c;
    --bbv-kraft-2: #232a25;
    --bbv-amber: #e5a35c;
    --bbv-amber-deep: #f0bd85;
    --bbv-amber-soft: #2c2013;
    --bbv-ink: #e8ece8;
    --bbv-ink-2: #a7b0a8;
    --bbv-ink-3: #737d75;
    --bbv-line: #2c352f;
    --bbv-line-2: #242c26;
    --bbv-red: #e08b7b;
    --bbv-red-soft: #301c18;
    --bbv-shadow: 0 18px 44px rgba(0, 0, 0, .5);
    --bbv-shadow-sm: 0 6px 16px rgba(0, 0, 0, .38);
}

.bbv-page {
    position: relative;
    color: var(--bbv-ink);
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.78;
    font-variant-numeric: tabular-nums;
    padding: 30px 30px 34px;
    margin-top: 22px;
    border: 1px solid var(--bbv-line);
    border-radius: 22px;
    box-shadow: var(--bbv-shadow);
    background:
        radial-gradient(760px 320px at 88% -6%, rgba(217, 122, 41, .13), transparent 60%),
        radial-gradient(600px 320px at 0% 10%, rgba(46, 110, 78, .10), transparent 55%),
        linear-gradient(180deg, var(--bbv-kraft-2), var(--bbv-kraft));
    overflow: hidden;
}
.bbv-page::before {
    /* 左侧书脊条纹 */
    content: "";
    position: absolute;
    inset: 0 auto 0 0;
    width: 10px;
    background: repeating-linear-gradient(180deg, var(--bbv-green) 0 74px, var(--bbv-amber) 74px 96px, var(--bbv-line) 96px 112px);
    opacity: .9;
}
.bbv-page * { box-sizing: border-box; }
.bbv-page h1, .bbv-page h2, .bbv-page h3 { margin: 0; line-height: 1.38; font-style: normal; }
.bbv-page a { color: var(--bbv-green-2); }

/* ---------- 首屏 ---------- */
.bbv-hero { display: grid; grid-template-columns: minmax(0, 1fr) 372px; gap: 26px; align-items: start; padding-left: 8px; }
.bbv-hero-copy { min-width: 0; }
.bbv-kicker {
    display: inline-block;
    font-size: 12px; font-weight: 700; letter-spacing: 2px;
    color: var(--bbv-amber-deep);
    background: var(--bbv-amber-soft);
    border: 1px solid color-mix(in srgb, var(--bbv-amber) 40%, transparent);
    border-radius: 999px;
    padding: 4px 14px;
    margin-bottom: 14px;
}
.bbv-page h1 { font-size: 30px; font-weight: 800; color: var(--bbv-green); letter-spacing: .5px; }
.bbv-lead { margin: 12px 0 0; color: var(--bbv-ink-2); font-size: 15px; }
.bbv-lead b { color: var(--bbv-ink); }
.bbv-tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 0; padding: 0; }
.bbv-tags li { font-size: 12.5px; color: var(--bbv-green); background: var(--bbv-green-soft); border-radius: 8px; padding: 3px 10px; }

.bbv-quick {
    margin-top: 20px;
    background: var(--bbv-kraft-2);
    border: 1px solid var(--bbv-line);
    border-left: 4px solid var(--bbv-amber);
    border-radius: 14px;
    padding: 14px 16px;
    box-shadow: var(--bbv-shadow-sm);
}
.bbv-quick-title { font-size: 13.5px; font-weight: 700; margin-bottom: 10px; }
.bbv-quick-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: flex-end; }
.bbv-quick-field { display: flex; flex-direction: column; gap: 4px; flex: 1 1 180px; }
.bbv-quick-field span { font-size: 12px; color: var(--bbv-ink-2); }
.bbv-quick-field input {
    border: 1px solid var(--bbv-line); border-radius: 10px;
    padding: 9px 12px; font-size: 14px; color: var(--bbv-ink);
    background: var(--bbv-kraft-2); min-width: 0;
}
.bbv-quick-field input:focus { outline: 2px solid color-mix(in srgb, var(--bbv-amber) 55%, transparent); outline-offset: 1px; }

/* ---------- 借书卡结论栏 ---------- */
.bbv-card {
    background: linear-gradient(170deg, var(--bbv-green) 0%, var(--bbv-green-2) 100%);
    border-radius: 16px;
    padding: 18px 16px 20px;
    color: #f2f6f0;
    box-shadow: var(--bbv-shadow-sm);
    position: relative;
}
.bbv-card::before {
    /* 借书卡打孔 */
    content: "";
    position: absolute; top: 12px; right: 14px;
    width: 10px; height: 10px; border-radius: 50%;
    background: color-mix(in srgb, var(--bbv-green) 40%, #000 12%);
    box-shadow: -16px 0 0 0 color-mix(in srgb, var(--bbv-green) 40%, #000 12%), -32px 0 0 0 color-mix(in srgb, var(--bbv-green) 40%, #000 12%);
}
.bbv-card-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 12px; }
.bbv-card-head b { font-size: 14.5px; letter-spacing: 1px; }
.bbv-card-head span { font-size: 11.5px; opacity: .75; }
.bbv-card-big { padding: 6px 0 10px; }
.bbv-card-big em { font-style: normal; font-size: 12px; background: rgba(255,255,255,.16); border-radius: 6px; padding: 2px 8px; margin-right: 8px; }
.bbv-card-big b { font-size: 26px; font-weight: 800; }
.bbv-card-sub { font-size: 12px; opacity: .8; }
.bbv-card-rows { margin-top: 12px; display: grid; gap: 6px; }
.bbv-card-row {
    display: flex; justify-content: space-between; font-size: 13px;
    padding: 7px 10px; border-radius: 8px;
    background: rgba(255, 255, 255, .10); border: 1px solid rgba(255, 255, 255, .15);
}
.bbv-card-row .k { opacity: .8; }
.bbv-card-row .v { font-weight: 700; font-family: var(--bbv-mono); }
.bbv-card-row.is-key { background: rgba(217, 122, 41, .3); border-color: color-mix(in srgb, var(--bbv-amber) 65%, transparent); }
.bbv-stamp {
    position: absolute; right: 14px; bottom: 12px;
    transform: rotate(-12deg);
    border: 2px solid var(--bbv-amber);
    color: var(--bbv-amber);
    border-radius: 8px;
    font-size: 12px; font-weight: 800; letter-spacing: 2px;
    padding: 3px 10px;
    opacity: .95;
    pointer-events: none;
}

/* ---------- 按钮 / 提示 ---------- */
.bbv-btn {
    border: 1px solid var(--bbv-line); border-radius: 10px;
    background: var(--bbv-kraft-2); color: var(--bbv-ink);
    font-size: 13.5px; font-weight: 600; padding: 9px 16px; cursor: pointer;
    transition: transform .12s ease, box-shadow .12s ease;
}
.bbv-btn:hover { transform: translateY(-1px); box-shadow: var(--bbv-shadow-sm); }
.bbv-btn--amber { background: var(--bbv-amber); border-color: var(--bbv-amber); color: #fff; }
.bbv-btn--ghost { background: transparent; }
.bbv-alert {
    margin-top: 18px; border-radius: 12px; padding: 12px 16px; font-size: 13.5px;
    background: var(--bbv-red-soft); color: var(--bbv-red);
    border: 1px solid color-mix(in srgb, var(--bbv-red) 35%, transparent);
}

/* ---------- 面板 ---------- */
.bbv-panel {
    margin-top: 22px;
    background: var(--bbv-kraft-2);
    border: 1px solid var(--bbv-line);
    border-radius: 16px;
    padding: 20px 22px 22px;
    box-shadow: var(--bbv-shadow-sm);
    position: relative;
}
.bbv-panel-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 6px; }
.bbv-pk {
    font-size: 11.5px; font-weight: 800; letter-spacing: 2px;
    color: var(--bbv-green); background: var(--bbv-green-soft);
    border-radius: 7px; padding: 3px 9px; flex: none;
}
.bbv-pk.is-amber { color: var(--bbv-amber-deep); background: var(--bbv-amber-soft); }
.bbv-panel-head h2 { font-size: 18.5px; font-weight: 800; }
.bbv-panel-head p, .bbv-panel-side { font-size: 12.5px; color: var(--bbv-ink-3); margin: 0; }
.bbv-panel-side { margin-left: auto; }

/* ---------- 表单 ---------- */
.bbv-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px 14px; margin-top: 12px; }
.bbv-field { display: flex; flex-direction: column; gap: 5px; min-width: 0; }
.bbv-label { font-size: 12.5px; color: var(--bbv-ink-2); }
.bbv-label i { font-style: normal; font-size: 11.5px; color: var(--bbv-ink-3); margin-left: 4px; }
.bbv-input, .bbv-select {
    border: 1px solid var(--bbv-line); border-radius: 10px;
    padding: 9px 12px; font-size: 14px; color: var(--bbv-ink);
    background: var(--bbv-kraft-2); min-width: 0; width: 100%;
}
.bbv-mono { font-family: var(--bbv-mono); }
.bbv-input:focus, .bbv-select:focus { outline: 2px solid color-mix(in srgb, var(--bbv-amber) 55%, transparent); outline-offset: 1px; }
.bbv-readonly {
    border: 1px dashed var(--bbv-line); border-radius: 10px;
    padding: 9px 12px; font-size: 13.5px; color: var(--bbv-ink-2);
    background: var(--bbv-kraft);
}

/* ---------- 四种方式卡 ---------- */
.bbv-ways { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 12px; margin-top: 14px; }
.bbv-way { border: 1px solid var(--bbv-line); border-radius: 14px; background: var(--bbv-kraft); padding: 14px 16px; }
.bbv-way-head { display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.bbv-way-icon { font-size: 18px; }
.bbv-way-head b { font-size: 15px; }
.bbv-way-note { font-size: 12px; color: var(--bbv-ink-3); }
.bbv-way-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px 12px; margin-top: 10px; }

/* ---------- 对比表 ---------- */
.bbv-table-wrap { overflow-x: auto; border: 1px solid var(--bbv-line); border-radius: 12px; margin-top: 12px; }
.bbv-table { width: 100%; border-collapse: collapse; font-size: 13px; min-width: 700px; }
.bbv-table thead th {
    background: var(--bbv-green-soft); color: var(--bbv-ink);
    text-align: left; padding: 10px 12px; font-size: 12.5px; white-space: nowrap;
}
.bbv-table thead th.is-mem { color: var(--bbv-green); }
.bbv-table tbody td { padding: 10px 12px; border-top: 1px solid var(--bbv-line-2); vertical-align: top; }
.bbv-table tbody tr.is-best { background: var(--bbv-amber-soft); }
.bbv-waycell b { display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.bbv-waycell .medal { font-size: 12px; background: var(--bbv-amber); color: #fff; border-radius: 6px; padding: 1px 7px; font-weight: 700; }
.bbv-cost { font-family: var(--bbv-mono); white-space: nowrap; font-weight: 700; }
.bbv-split { color: var(--bbv-ink-3); font-size: 12px; }
.bbv-trait { color: var(--bbv-ink-2); font-size: 12.5px; }
.bbv-cheap { color: var(--bbv-green); font-weight: 700; }

/* ---------- 平衡点卡片 ---------- */
.bbv-break-card {
    margin-top: 14px; border-radius: 14px; padding: 16px 18px;
    background: linear-gradient(135deg, var(--bbv-green-soft), var(--bbv-amber-soft));
    border: 1px dashed color-mix(in srgb, var(--bbv-green) 45%, transparent);
    font-size: 14px; line-height: 1.9;
}
.bbv-break-card:empty { display: none; }
.bbv-break-card b { font-size: 17px; font-family: var(--bbv-mono); }
.bbv-sub { font-size: 15px; margin: 20px 0 2px; display: flex; align-items: baseline; gap: 8px; }
.bbv-sub i { font-style: normal; }
.bbv-sub-note { font-size: 12px; color: var(--bbv-ink-3); font-weight: 400; }

/* ---------- 口径 / 介绍 / FAQ / 相关 ---------- */
.bbv-terms { display: grid; gap: 8px; margin-top: 12px; }
.bbv-term {
    display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 14px;
    padding: 10px 14px; border-radius: 10px; background: var(--bbv-kraft);
    border: 1px solid var(--bbv-line-2); font-size: 13.5px;
}
.bbv-term b { color: var(--bbv-green); }
.bbv-term span { color: var(--bbv-ink-2); }
.bbv-term span b { color: var(--bbv-ink); }
.bbv-intro-body p { margin: 8px 0 0; font-size: 14px; color: var(--bbv-ink-2); line-height: 1.95; }
.bbv-intro-body b { color: var(--bbv-ink); }
.bbv-faq { display: grid; gap: 8px; margin-top: 12px; }
.bbv-faq-item { border: 1px solid var(--bbv-line); border-radius: 12px; background: var(--bbv-kraft); padding: 0 16px; }
.bbv-faq-item summary { cursor: pointer; font-weight: 700; font-size: 14px; padding: 12px 0; list-style: none; position: relative; padding-right: 28px; }
.bbv-faq-item summary::-webkit-details-marker { display: none; }
.bbv-faq-item summary::after { content: "+"; position: absolute; right: 4px; top: 50%; transform: translateY(-50%); color: var(--bbv-ink-3); font-size: 16px; }
.bbv-faq-item[open] summary::after { content: "−"; }
.bbv-faq-a { font-size: 13.5px; color: var(--bbv-ink-2); padding: 0 0 12px; }
.bbv-faq-a b { color: var(--bbv-ink); }
.bbv-rel-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; margin-top: 12px; }
.bbv-rel-card {
    display: flex; flex-direction: column; gap: 4px;
    border: 1px solid var(--bbv-line); border-radius: 12px;
    background: var(--bbv-kraft); padding: 14px 16px; text-decoration: none;
    transition: transform .12s ease, box-shadow .12s ease;
}
.bbv-rel-card:hover { transform: translateY(-2px); box-shadow: var(--bbv-shadow-sm); }
.bbv-rel-card .ic { font-size: 20px; }
.bbv-rel-card b { font-size: 14px; color: var(--bbv-ink); }
.bbv-rel-card i { font-style: normal; font-size: 12.5px; color: var(--bbv-ink-3); }

/* ---------- Toast ---------- */
.bbv-toast {
    position: fixed; left: 50%; bottom: 32px; transform: translate(-50%, 16px);
    background: var(--bbv-ink); color: #fff; font-size: 13px;
    border-radius: 10px; padding: 10px 18px; opacity: 0; pointer-events: none;
    transition: opacity .2s, transform .2s; z-index: 60;
}
.bbv-toast.on { opacity: 1; transform: translate(-50%, 0); }
.bbv-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
    .bbv-hero { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
    .bbv-page { padding: 22px 16px 24px; border-radius: 16px; }
    .bbv-page h1 { font-size: 23px; }
    .bbv-panel { padding: 16px 14px 18px; }
    .bbv-term { grid-template-columns: 1fr; gap: 4px; }
    .bbv-quick-row { flex-direction: column; align-items: stretch; }
}

/* ---------- 打印 ---------- */
.bbv-sheet { display: none; }
@media print {
    body * { visibility: hidden !important; }
    .bbv-sheet, .bbv-sheet * { visibility: visible !important; }
    .bbv-sheet { display: block !important; position: absolute; inset: 0; padding: 24px; }
    .nav-header, .footer, .back-to-top, .detail-breadcrumb, #navEvadeBtn, .nav-evade-btn, #evadeFab, .evade-fab, #navMask, #clicaptcha-container { display: none !important; }
    .bbv-shead { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 2px solid #2e6e4e; padding-bottom: 8px; margin-bottom: 14px; }
    .bbv-shead b { font-size: 18px; }
    .bbv-shead span { font-size: 12px; color: #5c6560; }
    .bbv-stable { width: 100%; border-collapse: collapse; font-size: 13px; }
    .bbv-stable th, .bbv-stable td { border: 1px solid #c9c2b0; padding: 8px 10px; text-align: left; }
    .bbv-stable thead th { background: #e3f1e9; }
    .bbv-snote { margin-top: 14px; font-size: 12px; color: #5c6560; line-height: 1.9; }
    .bbv-sfoot { margin-top: 18px; font-size: 11px; color: #8e978f; text-align: right; }
}