/* ============================================================
 * FBACalculator.top — 全站样式
 * 设计：暖纸底 + 青绿主色 + 琥珀点缀的电商财务工具风，移动优先
 * ============================================================ */

:root {
  --primary: #0f766e;
  --primary-dark: #115e59;
  --accent: #d97706;
  --ink: #1c1917;
  --ink-2: #44403c;
  --ink-3: #78716c;
  --line: #e7e2dc;
  --bg: #faf8f5;
  --card: #ffffff;
  --pos: #047857;
  --neg: #b91c1c;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(28, 25, 23, .05), 0 6px 18px rgba(28, 25, 23, .06);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  font-size: 16px;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.25; color: var(--ink); }

.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* ---------- 头部 ---------- */
.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 62px; gap: 12px; }
.logo { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 18px; color: var(--ink); }
.logo:hover { text-decoration: none; }
.logo-text em { font-style: normal; color: var(--primary); }
.header-nav { display: flex; align-items: center; gap: 18px; }
.header-nav a { color: var(--ink-2); font-size: 14.5px; font-weight: 500; }
.header-nav a:hover { color: var(--primary); text-decoration: none; }
.lang-switch {
  border: 1px solid var(--line); border-radius: 8px; padding: 5px 8px;
  font-size: 13.5px; color: var(--ink-2); background: #fff; cursor: pointer;
}

/* ---------- Hero ---------- */
.hero { text-align: center; padding: 46px 0 24px; }
.hero h1 { font-size: clamp(26px, 4.6vw, 40px); margin: 0 0 12px; letter-spacing: -0.5px; }
.hero h1::after {
  content: ""; display: block; width: 64px; height: 4px; border-radius: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent)); margin: 14px auto 0;
}
.hero-desc { color: var(--ink-3); font-size: clamp(15px, 2vw, 17.5px); max-width: 760px; margin: 14px auto 0; }

/* ---------- 计算器 ---------- */
.tool-panel { margin-bottom: 44px; }
.load-error {
  background: #fef2f2; color: var(--neg); border: 1px solid #fecaca;
  padding: 12px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 14.5px;
}

/* 模式切换（吸顶大 Tab） */
.mode-bar {
  display: grid; grid-template-columns: 1fr 1fr; gap: 6px; max-width: 520px; margin: 0 auto 22px;
  background: #efeae3; border-radius: 12px; padding: 5px;
}
.mode-tab {
  border: 0; background: transparent; padding: 10px 12px; border-radius: 9px;
  font-size: 14.5px; font-weight: 600; color: var(--ink-3); cursor: pointer;
  transition: background .15s, color .15s;
}
.mode-tab.active { background: #fff; color: var(--primary); box-shadow: 0 1px 4px rgba(28,25,23,.14); }

.calc-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 22px; align-items: start; }

.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.card-pad { padding: 22px; }
.card-title { margin: 0 0 16px; font-size: 17px; font-weight: 700; }

/* 表单 */
.field { margin-bottom: 15px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.field label { display: block; font-size: 13.5px; font-weight: 600; color: var(--ink-2); margin-bottom: 5px; }
.field .help { display: block; font-size: 12px; color: var(--ink-3); margin-top: 3px; font-weight: 400; }
.help-block { margin: -8px 0 14px; }
.field input[type="number"], .field select {
  width: 100%; padding: 10px 12px; font-size: 15.5px;
  border: 1px solid var(--line); border-radius: 9px; background: #fff; color: var(--ink);
  transition: border-color .15s, box-shadow .15s;
}
.field input:focus, .field select:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, .14);
}

/* 尺寸三联动输入 */
.dims-row { display: flex; align-items: center; gap: 7px; }
.dims-row input { text-align: center; }
.dims-x { color: var(--ink-3); font-weight: 600; }
.dims-unit { color: var(--ink-3); font-size: 13px; }

/* 单选/复选芯片 */
.radio-group { display: flex; gap: 8px; flex-wrap: wrap; }
.radio-chip {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid var(--line); border-radius: 999px; padding: 7px 14px;
  font-size: 13.5px; cursor: pointer; color: var(--ink-2); background: #fff;
  transition: all .15s;
}
.radio-chip input { accent-color: var(--primary); margin: 0; }
.radio-chip:has(input:checked) { border-color: var(--primary); background: #f0fdfa; color: var(--primary); font-weight: 600; }
.check-row { margin-bottom: 14px; }
.check-chip {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13.5px;
  color: var(--ink-2); cursor: pointer; background: #fffbeb; border: 1px solid #fde68a;
  border-radius: 9px; padding: 8px 12px;
}
.check-chip input { accent-color: var(--accent); }

.adv-toggle {
  background: none; border: 0; color: var(--ink-3); font-size: 13.5px;
  cursor: pointer; padding: 4px 0; display: inline-flex; align-items: center; gap: 6px;
}
.adv-toggle::before { content: "▸"; transition: transform .15s; }
.adv-toggle[aria-expanded="true"]::before { transform: rotate(90deg); }
.adv-toggle:hover { color: var(--primary); }

/* FBM 对比输入块 */
.fbm-panel {
  margin-top: 16px; padding-top: 14px; border-top: 2px dashed var(--line);
}
.fbm-title { margin: 0 0 12px; font-size: 15px; color: var(--accent); }

/* ---------- 结果区 ---------- */
.result-hero {
  background: linear-gradient(135deg, #134e4a 0%, #0f766e 55%, #14b8a6 100%);
  border-radius: var(--radius); color: #fff; padding: 24px 22px;
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
  box-shadow: var(--shadow);
}
.result-hero .hero-label { font-size: 13.5px; opacity: .85; display: block; margin-bottom: 2px; }
.result-hero .hero-value { font-size: clamp(30px, 5vw, 42px); font-weight: 800; letter-spacing: -1px; line-height: 1.1; }
.hero-badge {
  font-size: 13.5px; font-weight: 700; padding: 7px 14px; border-radius: 999px;
  background: rgba(255,255,255,.16); white-space: nowrap;
}
.hero-badge.badge-pos { background: rgba(4, 120, 87, .35); }
.hero-badge.badge-neg { background: rgba(185, 28, 28, .35); }

/* 分段信息行 */
.tier-info {
  margin-top: 10px; font-size: 13px; color: var(--ink-3);
  display: flex; flex-wrap: wrap; gap: 6px 14px;
}
.tier-info b { color: var(--primary); font-weight: 700; }

.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 14px; }
.stat-card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; }
.stat-card .s-label { font-size: 12px; color: var(--ink-3); display: block; }
.stat-card .s-value { font-size: 16.5px; font-weight: 700; color: var(--ink); }

/* FBA vs FBM 对比面板 */
.compare-panel {
  margin-top: 14px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px;
}
.vs-col {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 14px 16px; text-align: center;
}
.vs-col .vs-name { display: block; font-size: 13px; font-weight: 700; letter-spacing: 1px; color: var(--ink-3); }
.vs-col .vs-value { display: block; font-size: 24px; font-weight: 800; color: var(--ink); margin: 4px 0 2px; }
.vs-col .vs-sub { display: block; font-size: 12.5px; color: var(--ink-3); }
.vs-col.vs-lead { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(15,118,110,.12); }
.vs-winner {
  grid-column: 1 / -1; text-align: center; font-size: 14px; font-weight: 700;
  color: var(--primary-dark); background: #f0fdfa; border: 1px solid #99f6e4;
  border-radius: 10px; padding: 9px 12px;
}
.vs-winner.vs-tie { color: var(--ink-3); background: #f5f5f4; border-color: var(--line); }

/* 费用条 */
.bar-wrap { margin-top: 16px; }
.fee-bar { display: flex; height: 12px; border-radius: 999px; overflow: hidden; background: #efeae3; }
.fee-seg { height: 100%; }

/* 明细表 */
.breakdown-card { margin-top: 16px; }
.bl-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 9px 0; border-bottom: 1px dashed var(--line); font-size: 14.5px;
}
.bl-row:last-child { border-bottom: 0; }
.bl-row .bl-label { color: var(--ink-2); }
.bl-row .bl-value { font-weight: 600; font-variant-numeric: tabular-nums; }
.bl-row.bl-total { font-size: 15.5px; }
.bl-row.bl-total .bl-label, .bl-row.bl-total .bl-value { font-weight: 800; color: var(--ink); }

.btn-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 14px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 1px solid var(--line); background: #fff; color: var(--ink-2);
  border-radius: 9px; padding: 11px 18px; font-size: 14.5px; font-weight: 600; cursor: pointer;
  transition: all .15s;
}
.btn:hover { border-color: var(--primary); color: var(--primary); }
.btn-alt { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn-alt:hover { background: var(--primary-dark); color: #fff; }

/* ---------- 内容区（SEO） ---------- */
.content-section { margin: 48px 0; }
.content-section h2 { font-size: clamp(20px, 3vw, 26px); margin-bottom: 14px; letter-spacing: -.3px; }
.content-section h3 { font-size: 17.5px; margin: 24px 0 8px; }
.content-section p { color: var(--ink-2); margin: 8px 0; }
.content-section ul { color: var(--ink-2); padding-left: 22px; }
.content-section li { margin: 4px 0; }

.guide-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.guide-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); }
.guide-card h3 { margin-top: 0; font-size: 16px; }
.guide-card p { font-size: 14.5px; color: var(--ink-2); margin-bottom: 0; }

.fee-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; margin: 18px 0; }
.fee-card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px; text-align: center; }
.fee-card .fc-value { font-size: 21px; font-weight: 800; color: var(--primary); }
.fee-card .fc-name { font-size: 12.5px; color: var(--ink-3); margin-top: 2px; }

.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); box-shadow: var(--shadow); }
table.fee-table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 520px; }
.fee-table th, .fee-table td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--line); }
.fee-table thead th { background: #f5f2ed; font-size: 12.5px; text-transform: uppercase; letter-spacing: .4px; color: var(--ink-3); }
.fee-table tbody tr:last-child td { border-bottom: 0; }
.fee-table tbody tr:hover { background: #faf8f5; }
.fee-table .tier-head td {
  background: #f0fdfa; color: var(--primary-dark); font-weight: 700; font-size: 13px;
}
.table-note { font-size: 12.5px; color: var(--ink-3); margin-top: 8px; }

/* FAQ */
.faq-item { background: var(--card); border: 1px solid var(--line); border-radius: 10px; margin-bottom: 10px; overflow: hidden; }
.faq-item summary {
  padding: 14px 18px; font-weight: 600; font-size: 15px; cursor: pointer; color: var(--ink);
  list-style: none; position: relative; padding-right: 40px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; position: absolute; right: 16px; top: 50%; transform: translateY(-50%);
  font-size: 20px; color: var(--ink-3); transition: transform .15s;
}
.faq-item[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq-item p { padding: 0 18px 14px; margin: 0; color: var(--ink-2); font-size: 14.5px; }

/* ---------- 合规页 ---------- */
.wrap { max-width: 780px; margin: 0 auto; padding: 0 20px; }
.legal { padding: 36px 0 50px; }
.legal h1 { font-size: 30px; margin-bottom: 6px; }
.legal .updated { color: var(--ink-3); font-size: 13.5px; margin-top: 0; }
.legal h2 { font-size: 19px; margin: 28px 0 8px; }
.legal p, .legal li { color: var(--ink-2); font-size: 15px; }
.legal ul { padding-left: 22px; }
.legal .callout {
  background: #f0fdfa; border-left: 4px solid var(--primary);
  padding: 12px 16px; border-radius: 0 8px 8px 0; font-size: 15px;
}

/* ---------- 页脚 ---------- */
.site-footer { background: #1c1917; color: #a8a29e; margin-top: 60px; }
.footer-inner { padding: 34px 0 30px; }
.footer-inner p { margin: 6px 0; font-size: 13.5px; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 6px 20px; margin: 12px 0; }
.footer-nav a { color: #d6d3d1; font-size: 13.5px; }
.footer-nav a:hover { color: #fff; }
.disclaimer { color: #78716c; font-size: 12.5px !important; }

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 34px; transform: translate(-50%, 20px);
  background: var(--ink); color: #fff; padding: 10px 22px; border-radius: 999px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: all .25s; z-index: 100;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .calc-grid { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: 1fr 1fr; }
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .header-nav a { display: none; }
  .hero { padding: 30px 0 18px; }
  .field-row { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: 1fr; }
  .result-hero { flex-direction: column; align-items: flex-start; }
  .compare-panel { grid-template-columns: 1fr; }
  .vs-winner { grid-column: auto; }
  .btn-row { grid-template-columns: 1fr; }
  .card-pad { padding: 16px; }
}