* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #f4f6f9;
  --card-bg: #ffffff;
  --text-main: #1f2430;
  --text-muted: #6b7280;
  --border: #e5e8ee;
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --income: #16a34a;
  --income-bg: #ecfdf3;
  --expense: #dc2626;
  --expense-bg: #fef2f2;
  --radius: 10px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text-main);
  line-height: 1.5;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

.header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  margin-bottom: 28px;
}

.logo {
  font-size: 22px;
  font-weight: 700;
}

.summary-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.card-label {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.card-value {
  font-size: 26px;
  font-weight: 700;
}

.card-income .card-value {
  color: var(--income);
}

.card-expense .card-value {
  color: var(--expense);
}

/* ===== Section Titles ===== */
.section-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 14px;
}

.form-section {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 28px;
}

.transaction-form {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
}

.form-group input,
.form-group select {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: #fff;
  color: var(--text-main);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.form-error {
  grid-column: 1 / -1;
  color: var(--expense);
  font-size: 13px;
  min-height: 18px;
}

.form-actions {
  grid-column: 1 / -1;
  display: flex;
  gap: 10px;
}

.btn {
  padding: 10px 18px;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
  font-family: inherit;
}

.btn:hover {
  transform: translateY(-1px);
}

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

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

.btn-secondary {
  background: #f1f2f6;
  color: var(--text-main);
}

.btn-secondary:hover {
  background: #e5e7eb;
}

.controls-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.search-input {
  flex: 1;
  min-width: 200px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: #fff;
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
}

.filter-buttons {
  display: flex;
  gap: 8px;
}

.filter-btn {
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
  font-family: inherit;
}

.filter-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.filter-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.list-section {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 40px;
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 40px 10px;
  font-size: 14px;
}

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

.transaction-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.transaction-table th {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 2px solid var(--border);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  white-space: nowrap;
}

.transaction-table td {
  padding: 12px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

.transaction-table tbody tr:hover {
  background: #fafbfe;
}

.type-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  text-transform: capitalize;
}

.type-badge.income {
  background: var(--income-bg);
  color: var(--income);
}

.type-badge.expense {
  background: var(--expense-bg);
  color: var(--expense);
}

.amount-income {
  color: var(--income);
  font-weight: 600;
}

.amount-expense {
  color: var(--expense);
  font-weight: 600;
}

.action-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 15px;
  padding: 4px 6px;
  border-radius: 6px;
}

.action-btn:hover {
  background: var(--bg);
}

@media (max-width: 720px) {
  .summary-cards {
    grid-template-columns: 1fr;
  }

  .transaction-form {
    grid-template-columns: 1fr;
  }

  .controls-section {
    flex-direction: column;
    align-items: stretch;
  }

  .filter-buttons {
    justify-content: stretch;
  }

  .filter-btn {
    flex: 1;
  }
}