/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  :root {
    --primary: #3b82f6;
    --success: #059669;
    --danger: #dc2626;
    --warning: #f59e0b;
    --neutral: #64748b;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.05);
  }
  
  body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
  }
  
  /* ===== Page d'authentification ===== */
  .auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1e293b 0%, #3b82f6 100%);
    padding: 1rem;
  }
  
  .auth-container {
    width: 100%;
    max-width: 420px;
  }
  
  .auth-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 2.5rem 2rem;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  }
  
  .auth-card h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    text-align: center;
    margin-bottom: 0.25rem;
  }
  
  .subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 2rem;
    font-size: 0.95rem;
  }
  
  .form-group {
    margin-bottom: 1.25rem;
  }
  
  .form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.35rem;
  }
  
  .form-group input,
  .form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1.5px solid var(--border);
    border-radius: 8px;
    font-size: 0.95rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: #fff;
  }
  
  .form-group input:focus,
  .form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.15);
  }
  
  .btn-primary {
    width: 100%;
    padding: 0.85rem;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
  }
  
  .btn-primary:hover {
    background: #2563eb;
  }
  
  .btn-primary:active {
    transform: scale(0.98);
  }
  
  .btn-secondary {
    width: 100%;
    padding: 0.85rem;
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
  }
  
  .btn-secondary:hover {
    background: var(--primary);
    color: #fff;
  }
  
  .message {
    margin-top: 1rem;
    padding: 0.75rem;
    border-radius: 8px;
    font-size: 0.9rem;
    text-align: center;
    display: none;
  }
  
  .message.error {
    display: block;
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
  }
  
  .message.success {
    display: block;
    background: #f0fdf4;
    color: var(--success);
    border: 1px solid #bbf7d0;
  }
  
  .auth-footer {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-light);
  }
  
  .auth-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
  }
  
  .auth-footer a:hover {
    text-decoration: underline;
  }
  
  .hidden {
    display: none !important;
  }
  
  hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 1.5rem 0;
  }
  
  /* ===== Dashboard ===== */
  .dashboard-page {
    background: var(--bg);
  }
  
  .app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 2rem;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 10;
  }
  
  .app-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
  }
  
  .header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
  }
  
  #current-user {
    font-weight: 500;
    color: var(--text-light);
    font-size: 0.9rem;
  }
  
  .btn-logout {
    padding: 0.5rem 1rem;
    background: transparent;
    color: var(--danger);
    border: 1.5px solid var(--danger);
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
  }
  
  .btn-logout:hover {
    background: var(--danger);
    color: #fff;
  }
  
  .dashboard-main {
    max-width: 1100px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
  }
  
  /* KPI */
  .kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
    margin-bottom: 2rem;
  }
  
  .kpi-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    border-left: 4px solid var(--primary);
  }
  
  .kpi-card.credit {
    border-left-color: var(--success);
  }
  
  .kpi-card.debit {
    border-left-color: var(--danger);
  }
  
  .kpi-label {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }
  
  .kpi-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text);
  }
  
  /* Formulaire */
  .add-transaction {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.75rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
  }
  
  .add-transaction h2 {
    font-size: 1.2rem;
    margin-bottom: 1.25rem;
  }
  
  .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1.25rem;
  }
  
  /* Historique */
  .history {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.75rem;
    box-shadow: var(--shadow);
  }
  
  .history-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.25rem;
  }
  
  .history-header h2 {
    font-size: 1.2rem;
  }
  
  .btn-danger {
    padding: 0.5rem 1rem;
    background: transparent;
    color: var(--danger);
    border: 1.5px solid var(--danger);
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
  }
  
  .btn-danger:hover {
    background: var(--danger);
    color: #fff;
  }
  
  .transactions-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
  }
  
  .transaction-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.85rem 1rem;
    border-radius: 8px;
    background: #f8fafc;
    border: 1px solid var(--border);
    transition: transform 0.15s;
  }
  
  .transaction-item:hover {
    transform: translateX(4px);
  }
  
  .transaction-item.credit {
    border-left: 3px solid var(--success);
  }
  
  .transaction-item.debit {
    border-left: 3px solid var(--danger);
  }
  
  .tx-info {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
  }
  
  .tx-label {
    font-weight: 600;
    font-size: 0.95rem;
  }
  
  .tx-date {
    font-size: 0.8rem;
    color: var(--text-light);
  }
  
  .tx-amount {
    font-weight: 700;
    font-size: 1rem;
  }
  
  .tx-amount.credit {
    color: var(--success);
  }
  
  .tx-amount.debit {
    color: var(--danger);
  }
  
  .tx-delete {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: background 0.2s, color 0.2s;
  }
  
  .tx-delete:hover {
    background: #fee2e2;
    color: var(--danger);
  }
  
  .empty-message {
    text-align: center;
    color: var(--text-light);
    padding: 2rem;
    font-size: 0.95rem;
  }
  
  /* ===== Responsive ===== */
  @media (max-width: 768px) {
    .app-header {
      padding: 0.85rem 1rem;
    }
  
    .dashboard-main {
      padding: 1.25rem 1rem;
    }
  
    .form-row {
      grid-template-columns: 1fr;
    }
  
    .kpi-grid {
      grid-template-columns: 1fr;
    }
  
    .auth-card {
      padding: 2rem 1.5rem;
    }
  }