:root {
    --color-blue: #3b82f6;
    --color-blue-light: #eff6ff;
    --color-navy: #1e3a8a;
    --color-navy-dark: #16296b;
    --color-white: #ffffff;
    --color-bg: #f4f7fc;
    --color-text: #1f2937;
    --color-muted: #6b7280;
    --color-border: #e5e7eb;
    --color-success: #16a34a;
    --color-warning: #f59e0b;
    --color-danger: #dc2626;
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
    --shadow-soft: 0 4px 16px rgba(30, 58, 138, 0.08);
    --shadow-card: 0 2px 8px rgba(30, 58, 138, 0.06);
    --transition: all 0.18s ease;
  }

  * { box-sizing: border-box; }

  html, body {
    margin: 0;
    padding: 0;
    font-family: 'Sarabun', 'Segoe UI', Tahoma, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
  }

  #app-root { min-height: 100vh; }

  .hidden { display: none !important; }

  a { text-decoration: none; color: inherit; }

  /* ---------- Buttons (3D style) ---------- */
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    background: var(--color-blue);
    color: #fff;
    box-shadow: 0 4px 0 rgba(0,0,0,0.12), var(--shadow-card);
    transform: translateY(0);
    transition: var(--transition);
  }
  .btn:hover { transform: translateY(-2px); box-shadow: 0 6px 0 rgba(0,0,0,0.12), var(--shadow-soft); }
  .btn:active { transform: translateY(2px); box-shadow: 0 1px 0 rgba(0,0,0,0.12); }
  .btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

  .btn-primary { background: var(--color-navy); }
  .btn-success { background: var(--color-success); }
  .btn-warning { background: var(--color-warning); }
  .btn-danger  { background: var(--color-danger); }
  .btn-outline { background: #fff; color: var(--color-navy); border: 1px solid var(--color-border); box-shadow: 0 3px 0 rgba(0,0,0,0.05); }
  .btn-block { width: 100%; }
  .btn-sm { padding: 6px 12px; font-size: 12px; }

  /* ---------- Cards ---------- */
  .card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 20px;
  }

  /* ---------- Login / Auth screens ---------- */
  .auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-blue) 100%);
    padding: 20px;
  }
  .auth-card {
    position: relative;
    width: 100%;
    max-width: 380px;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: 0 12px 40px rgba(0,0,0,0.18);
    padding: 32px 28px;
  }
  /* ---------- ท้ายการ์ด: ปุ่มล้างข้อมูล + เวอร์ชัน ---------- */
  .auth-footer {
    margin-top: 20px;
    padding-top: 14px;
    border-top: 1px solid var(--color-border);
  }
  .auth-version {
    text-align: center;
    font-size: 11px;
    color: var(--color-muted);
    font-family: 'Courier New', monospace;
    letter-spacing: 0.5px;
    margin: 10px 0 0;
  }
  .auth-logo {
    text-align: center;
    margin-bottom: 8px;
    font-size: 28px;
  }
  /* ชื่อโปรแกรม — เด่นที่สุดในการ์ด */
  .auth-title {
    text-align: center;
    font-size: 30px;
    font-weight: 800;
    letter-spacing: -0.5px;
    color: var(--color-navy);
    margin: 0 0 4px;
    line-height: 1.2;
  }
  .auth-subtitle {
    text-align: center;
    font-size: 14px;
    font-weight: 600;
    color: var(--color-blue);
    margin: 0 0 10px;
  }
  /* เครดิตผู้พัฒนา — รองลงมาจากชื่อโปรแกรม */
  .auth-credit {
    text-align: center;
    font-size: 12px;
    font-weight: 600;
    color: var(--color-muted);
    line-height: 1.6;
    margin: 0 0 20px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--color-border);
  }
  .form-group { margin-bottom: 14px; }
  .form-label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; color: var(--color-text); }
  .form-input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    transition: var(--transition);
    background: #fff;
  }
  .form-input:focus { outline: none; border-color: var(--color-blue); box-shadow: 0 0 0 3px var(--color-blue-light); }

  /* ช่องกรอกวันที่/เวลาแบบไทย — ใช้ตัวเลขความกว้างเท่ากันเพื่อให้อ่านง่าย */
  .thai-date {
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.5px;
  }
  .thai-date::placeholder { letter-spacing: normal; font-size: 13px; }
  .auth-links { display: flex; justify-content: space-between; margin-top: 14px; font-size: 13px; }
  .auth-links a, .auth-links button.link-btn {
    color: var(--color-blue); background: none; border: none; cursor: pointer; font-size: 13px; padding: 0;
  }
  .auth-error {
    background: #fef2f2; color: var(--color-danger); border: 1px solid #fecaca;
    padding: 8px 12px; border-radius: var(--radius-sm); font-size: 13px; margin-bottom: 12px;
  }
  .auth-success {
    background: #f0fdf4; color: var(--color-success); border: 1px solid #bbf7d0;
    padding: 8px 12px; border-radius: var(--radius-sm); font-size: 13px; margin-bottom: 12px;
  }

  /* ---------- App shell ---------- */
  .app-shell { display: flex; min-height: 100vh; }

  .sidebar {
    width: 220px;
    background: var(--color-navy-dark);
    color: #fff;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
  }
  .sidebar-brand {
    display: flex; align-items: center; gap: 8px;
    padding: 20px 18px; font-weight: 700; font-size: 16px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
  }
  .sidebar-nav { flex: 1; padding: 10px; }
  .sidebar-nav .nav-item {
    display: flex; align-items: center; gap: 10px;
    padding: 11px 14px; border-radius: var(--radius-sm);
    font-size: 14px; color: rgba(255,255,255,0.82); cursor: pointer;
    margin-bottom: 2px; transition: var(--transition);
  }
  .sidebar-nav .nav-item:hover { background: rgba(255,255,255,0.08); color: #fff; }
  .sidebar-nav .nav-item.active { background: var(--color-blue); color: #fff; }

  .main-content { flex: 1; display: flex; flex-direction: column; min-width: 0; }

  .topbar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 14px 24px; background: #fff; box-shadow: var(--shadow-card);
  }
  .topbar-user { display: flex; align-items: center; gap: 10px; font-size: 14px; }
  .avatar {
    width: 34px; height: 34px; border-radius: 50%; background: var(--color-blue-light);
    display: flex; align-items: center; justify-content: center; color: var(--color-navy); font-weight: 700;
  }

  .content-area { padding: 24px; flex: 1; overflow-y: auto; }

  /* ---------- Status badges ---------- */
  .badge { display: inline-block; padding: 3px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; }
  .badge-pending { background: #fef3c7; color: #b45309; }
  .badge-approved { background: #dcfce7; color: #15803d; }
  .badge-suspended { background: #fee2e2; color: #b91c1c; }
  .badge-rejected { background: #f3f4f6; color: #6b7280; }

  /* ---------- Table ---------- */
  table.data-table { width: 100%; border-collapse: collapse; font-size: 13px; }
  table.data-table th {
    text-align: left; padding: 10px 12px; background: var(--color-blue-light);
    color: var(--color-navy); font-weight: 700; border-bottom: 1px solid var(--color-border);
  }
  table.data-table td { padding: 10px 12px; border-bottom: 1px solid var(--color-border); }
  table.data-table tr:hover td { background: #fafbff; }

  /* ---------- Checkbox เลือกหลายรายการ ---------- */
  table.data-table input[type="checkbox"] {
    width: 17px; height: 17px; cursor: pointer; accent-color: var(--color-blue); vertical-align: middle;
  }
  table.data-table input[type="checkbox"]:disabled { cursor: not-allowed; opacity: 0.35; }
  table.data-table tr:has(.row-check:checked) td { background: var(--color-blue-light); }

  /* ---------- Responsive ---------- */
  @media (max-width: 768px) {
    .app-shell { flex-direction: column; }
    .sidebar { width: 100%; flex-direction: row; overflow-x: auto; }
    .sidebar-brand { display: none; }
    .sidebar-nav { display: flex; padding: 6px; }
    .sidebar-nav .nav-item { white-space: nowrap; }
    .content-area { padding: 14px; }
  }

  .spinner {
    width: 18px; height: 18px; border: 3px solid rgba(255,255,255,0.4);
    border-top-color: #fff; border-radius: 50%; animation: spin 0.7s linear infinite;
  }
  @keyframes spin { to { transform: rotate(360deg); } }