:root {
  --bg: #f4f6f9;
  --surface: #ffffff;
  --border: #e5e7eb;
  --border-strong: #d1d5db;
  --text: #111827;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --accent: #f59e0b;
  --accent-soft: #fef3c7;
  --week-soft: #fffbeb;
  --success: #059669;
  --danger: #dc2626;
  --row-hover: #f9fafb;
  --total-bg: #f3f4f6;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --radius: 10px;
  --font: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  --mono: "SF Mono", "Menlo", "Consolas", monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

.app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px 20px 48px;
}

/* Header */
.header {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  box-shadow: var(--shadow);
}

.header h1 {
  margin: 0 0 4px;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.header-right {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: flex-end;
}

.rate-box, .month-box {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.rate-box label, .month-box label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.rate-row {
  display: flex;
  gap: 8px;
  align-items: center;
}

#exchangeRate, #statMonth {
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 0.95rem;
  font-family: var(--mono);
  background: #fff;
  min-width: 120px;
}

#exchangeRate:focus, #statMonth:focus {
  outline: 2px solid rgba(37, 99, 235, 0.25);
  border-color: var(--primary);
}

.rate-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Toolbar */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.toolbar-left, .toolbar-right {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 8px 14px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: background .15s, border-color .15s, color .15s;
  background: #fff;
  color: var(--text);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-hover); }

.btn-secondary {
  background: #eff6ff;
  color: var(--primary);
  border-color: #bfdbfe;
}
.btn-secondary:hover { background: #dbeafe; }

.btn-ghost {
  background: #fff;
  border-color: var(--border-strong);
  color: var(--text);
}
.btn-ghost:hover { background: var(--row-hover); }

.btn-danger-ghost {
  background: #fff;
  border-color: #fecaca;
  color: var(--danger);
}
.btn-danger-ghost:hover { background: #fef2f2; }

.file-btn { display: inline-flex; align-items: center; }

/* Panel */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  overflow: hidden;
}

.panel-title {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  align-items: baseline;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
}

.panel-title h2 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
}

.hint {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.table-wrap {
  overflow-x: auto;
}

/* Table */
.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 900px;
  font-size: 0.875rem;
}

.data-table th,
.data-table td {
  border: 1px solid var(--border);
  padding: 0;
  vertical-align: middle;
  text-align: center;
}

.data-table thead th {
  background: var(--week-soft);
  font-weight: 700;
  padding: 10px 8px;
  white-space: nowrap;
}

.data-table thead th.col-month {
  background: var(--accent);
  color: #1f2937;
}

.data-table thead th.col-week {
  background: #fde68a;
  color: #1f2937;
}

.data-table thead th.col-note,
.data-table thead th.col-name {
  background: #f3f4f6;
}

.data-table thead tr.subhead th {
  background: #fafafa;
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--text-muted);
  padding: 6px 8px;
}

.data-table tbody td {
  background: #fff;
}

.data-table tbody tr:hover td {
  background: var(--row-hover);
}

.data-table tfoot td {
  background: var(--total-bg);
  font-weight: 700;
  padding: 10px 8px;
}

.cell-name {
  text-align: left !important;
  padding: 6px 10px !important;
  min-width: 140px;
  font-weight: 600;
  white-space: nowrap;
}

.cell-name input {
  width: 100%;
  border: 1px solid transparent;
  background: transparent;
  font: inherit;
  font-weight: 600;
  padding: 6px 4px;
  border-radius: 6px;
}

.cell-name input:hover,
.cell-name input:focus {
  border-color: var(--border-strong);
  background: #fff;
  outline: none;
}

.cell-note {
  text-align: left !important;
  min-width: 160px;
  padding: 4px 8px !important;
}

.cell-note input {
  width: 100%;
  border: 1px solid transparent;
  background: transparent;
  font: inherit;
  padding: 6px 4px;
  border-radius: 6px;
  color: var(--text-muted);
}

.cell-note input:hover,
.cell-note input:focus {
  border-color: var(--border-strong);
  background: #fff;
  outline: none;
  color: var(--text);
}

.cell-input,
.cell-readonly {
  min-width: 100px;
}

.cell-input input {
  width: 100%;
  border: 1px solid transparent;
  background: transparent;
  font-family: var(--mono);
  font-size: 0.85rem;
  text-align: right;
  padding: 8px 10px;
  border-radius: 0;
}

.cell-input input:hover {
  background: #eff6ff;
}

.cell-input input:focus {
  outline: 2px solid rgba(37, 99, 235, 0.35);
  outline-offset: -2px;
  background: #eff6ff;
}

.cell-readonly {
  font-family: var(--mono);
  font-size: 0.85rem;
  text-align: right;
  padding: 8px 10px !important;
  color: #374151;
  background: #fafafa !important;
}

.cell-readonly.cny {
  color: #b45309;
}

.cell-readonly.month-cny {
  color: #92400e;
  font-weight: 700;
  background: #fffbeb !important;
}

.cell-readonly.month-usd {
  font-weight: 700;
  background: #fffbeb !important;
}

.currency-tag {
  display: inline-flex;
  gap: 4px;
  align-items: center;
  justify-content: flex-end;
  width: 100%;
}

select.currency-select {
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.75rem;
  padding: 2px 4px;
  background: #fff;
  color: var(--text-muted);
  max-width: 72px;
}

.row-actions {
  display: inline-flex;
  gap: 4px;
  margin-left: 6px;
  opacity: 0.35;
  transition: opacity .15s;
}

tr:hover .row-actions { opacity: 1; }

.icon-btn {
  border: none;
  background: transparent;
  cursor: pointer;
  color: var(--text-muted);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.8rem;
  line-height: 1;
}

.icon-btn:hover {
  background: #fee2e2;
  color: var(--danger);
}

.week-label-edit {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.week-label-edit input {
  border: 1px solid transparent;
  background: transparent;
  font: inherit;
  font-weight: 700;
  text-align: center;
  width: 140px;
  border-radius: 4px;
  padding: 2px 4px;
}

.week-label-edit input:hover,
.week-label-edit input:focus {
  border-color: rgba(0,0,0,.15);
  background: rgba(255,255,255,.7);
  outline: none;
}

.week-remove {
  border: none;
  background: rgba(0,0,0,.06);
  color: #6b7280;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 12px;
  line-height: 1;
  padding: 0;
}

.week-remove:hover {
  background: #fee2e2;
  color: var(--danger);
}

.empty-tip {
  padding: 28px;
  text-align: center;
  color: var(--text-muted);
}

.footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.78rem;
  padding: 8px;
}

/* toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: #111827;
  color: #fff;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 0.875rem;
  box-shadow: 0 8px 24px rgba(0,0,0,.18);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity .2s, transform .2s;
  z-index: 100;
  pointer-events: none;
}
.toast.show {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 720px) {
  .header { padding: 16px; }
  .app { padding: 12px 10px 40px; }
}

.save-status {
  font-size: 0.8rem;
  color: #6b7280;
  margin-left: 8px;
  font-weight: 500;
}
.save-status.saving { color: #d97706; }
.save-status.saved { color: #059669; }
.save-status.error { color: #dc2626; }
.save-status.loading { color: #2563eb; }