:root {
  color-scheme: light;
  --ink: #172026;
  --muted: #64717a;
  --line: #d8e0e4;
  --paper: #ffffff;
  --bg: #f5f7f8;
  --brand: #146b65;
  --accent: #b8324a;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
}
a { color: var(--brand); }
.shell { width: min(960px, calc(100% - 28px)); margin: 0 auto; padding: 24px 0 48px; }
.topbar { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 20px; }
.panel { background: var(--paper); border: 1px solid var(--line); border-radius: 8px; padding: 22px; margin-bottom: 16px; }
h1 { font-size: clamp(28px, 5vw, 44px); line-height: 1.05; margin: 0 0 20px; letter-spacing: 0; }
h2 { margin: 0 0 10px; font-size: 22px; letter-spacing: 0; }
.form { display: grid; gap: 14px; }
.form.inline { grid-template-columns: 1fr auto; align-items: end; }
label { display: grid; gap: 6px; color: var(--muted); font-size: 14px; }
input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 12px 13px;
  font: inherit;
  color: var(--ink);
  background: #fff;
}
button, .paypal {
  border: 0;
  border-radius: 6px;
  padding: 12px 16px;
  background: var(--brand);
  color: #fff;
  font-weight: 700;
  font: inherit;
  text-decoration: none;
  text-align: center;
  cursor: pointer;
}
button.secondary { background: #edf4f3; color: var(--brand); }
.message { min-height: 24px; color: var(--muted); }
.hidden { display: none !important; }
.summary-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 16px; }
.summary-grid div { border: 1px solid var(--line); border-radius: 6px; padding: 12px; min-width: 0; }
.summary-grid span { display: block; color: var(--muted); font-size: 13px; margin-bottom: 5px; }
.summary-grid strong { font-size: 21px; overflow-wrap: anywhere; }
.order-code, .pay-code { color: var(--accent); font-variant-numeric: tabular-nums; letter-spacing: 0; }
.pay-code { font-size: 40px; font-weight: 800; margin: 8px 0 16px; }
.tree-actions { display: flex; gap: 8px; margin-bottom: 10px; }
.file-tree { border-top: 1px solid var(--line); }
.tree-row { display: grid; grid-template-columns: 28px 1fr auto; gap: 10px; align-items: center; min-height: 36px; border-bottom: 1px solid #edf1f2; }
.tree-row .name { overflow-wrap: anywhere; }
.tree-row .size { color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.progress { border-left: 4px solid var(--brand); padding: 10px 12px; background: #edf4f3; color: #243438; margin-bottom: 14px; }
.wechat { margin-top: 18px; display: grid; gap: 10px; max-width: 260px; }
.wechat img { width: 220px; max-width: 100%; border: 1px solid var(--line); border-radius: 6px; }
@media (max-width: 720px) {
  .form.inline, .summary-grid { grid-template-columns: 1fr; }
  .panel { padding: 16px; }
  .tree-row { grid-template-columns: 28px 1fr; }
  .tree-row .size { grid-column: 2; }
}