/* ============ RESET & BASE ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }

:root {
  --color-bg: #f7f9fc;
  --color-surface: #ffffff;
  --color-surface-alt: #f0f4f9;
  --color-border: #e1e7ef;
  --color-border-strong: #cbd5e0;
  --color-text: #1a202c;
  --color-text-muted: #64748b;
  --color-text-light: #94a3b8;
  --color-primary: #1f4e78;
  --color-primary-hover: #163d5e;
  --color-primary-light: #e7eff7;
  --color-danger: #dc2626;
  --color-danger-bg: #fef2f2;
  --color-warning: #d97706;
  --color-warning-bg: #fffbeb;
  --color-success: #059669;
  --color-success-bg: #ecfdf5;
  --color-hot: #fbbf24;
  --color-hot-bg: #fffbeb;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.08);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
}

/* ============ LOGIN PAGE ============ */
.auth-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: linear-gradient(135deg, #f0f4f9 0%, #e7eff7 100%);
}

.auth-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 40px;
  width: 100%;
  max-width: 420px;
}

.auth-logo {
  display: block;
  height: 60px;
  margin: 0 auto 24px;
  object-fit: contain;
}

.auth-title {
  font-size: 24px;
  font-weight: 700;
  text-align: center;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.auth-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  font-size: 14px;
}

.auth-form { display: flex; flex-direction: column; gap: 16px; }

.auth-label {
  display: block;
}

.auth-label span {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.auth-label input {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  background: var(--color-surface);
  color: var(--color-text);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.auth-label input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.auth-error {
  background: var(--color-danger-bg);
  color: var(--color-danger);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  border: 1px solid #fecaca;
}

.auth-success {
  background: var(--color-success-bg);
  color: var(--color-success);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  border: 1px solid #a7f3d0;
}

/* ============ BUTTONS ============ */
.btn-primary {
  background: var(--color-primary);
  color: white;
  border: none;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
  font-family: inherit;
}

.btn-primary:hover:not(:disabled) { background: var(--color-primary-hover); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; }

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
}

.btn-secondary:hover { background: var(--color-surface-alt); }

.btn-icon {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s;
}

.btn-icon:hover { background: var(--color-surface-alt); border-color: var(--color-border-strong); }
.btn-icon svg { flex-shrink: 0; }

/* ============ TOP BAR ============ */
.topbar {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 12px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar-left { display: flex; align-items: center; gap: 16px; }
.topbar-logo { height: 40px; object-fit: contain; }
.topbar-right { display: flex; align-items: center; gap: 12px; }

/* ============ USER MENU ============ */
.user-menu { position: relative; }

.btn-user {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 6px 12px 6px 6px;
  border-radius: 20px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  color: var(--color-text);
}

.btn-user:hover { background: var(--color-surface-alt); }

.user-avatar {
  width: 28px;
  height: 28px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
}

.user-name { font-weight: 500; }

.dropdown {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  min-width: 180px;
  overflow: hidden;
  z-index: 20;
}

.dropdown-item {
  display: block;
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 10px 14px;
  font-size: 13px;
  cursor: pointer;
  color: var(--color-text);
  font-family: inherit;
}

.dropdown-item:hover { background: var(--color-surface-alt); }

/* ============ SYNC BAR ============ */
.sync-bar {
  background: var(--color-primary-light);
  color: var(--color-primary);
  padding: 6px 24px;
  font-size: 12px;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.sync-bar.error { background: var(--color-danger-bg); color: var(--color-danger); }
.sync-bar.success { background: var(--color-success-bg); color: var(--color-success); }

/* ============ PARENT TABS ============ */
.parent-tabs {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0 24px;
  display: flex;
  gap: 4px;
}

.parent-tab {
  background: none;
  border: none;
  padding: 14px 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  font-family: inherit;
  border-bottom: 3px solid transparent;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.15s;
}

.parent-tab:hover { color: var(--color-text); }
.parent-tab.active { color: var(--color-primary); border-bottom-color: var(--color-primary); }
.tab-icon { font-size: 16px; }

/* ============ SUB TABS ============ */
.sub-tabs {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0 24px;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.sub-tab {
  background: none;
  border: none;
  padding: 10px 14px;
  font-size: 13px;
  color: var(--color-text-muted);
  cursor: pointer;
  font-family: inherit;
  border-bottom: 2px solid transparent;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  transition: all 0.15s;
}

.sub-tab:hover { color: var(--color-text); }
.sub-tab.active { color: var(--color-primary); border-bottom-color: var(--color-primary); font-weight: 600; }

.badge {
  background: var(--color-surface-alt);
  color: var(--color-text-muted);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 11px;
  font-weight: 600;
}

.sub-tab.active .badge { background: var(--color-primary); color: white; }

/* ============ SEARCH BAR ============ */
.search-bar {
  background: var(--color-surface);
  padding: 12px 24px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 16px;
}

.search-bar input {
  flex: 1;
  max-width: 400px;
  padding: 8px 14px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
}

.search-bar input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.result-count { color: var(--color-text-muted); font-size: 12px; }

/* ============ TABLE ============ */
.table-wrapper {
  padding: 16px 24px 40px;
  position: relative;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.data-table thead {
  background: var(--color-surface-alt);
  border-bottom: 2px solid var(--color-border);
}

.data-table th {
  padding: 11px 14px;
  text-align: left;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--color-border);
  font-size: 13px;
  vertical-align: middle;
}

.data-table tbody tr:hover { background: var(--color-primary-light); }
.data-table tbody tr:last-child td { border-bottom: none; }

.cell-name { font-weight: 600; color: var(--color-text); }
.cell-muted { color: var(--color-text-muted); font-size: 12px; }
.cell-mono { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 12px; }

.days-overdue { color: var(--color-danger); font-weight: 700; }
.days-upcoming { color: var(--color-warning); font-weight: 600; }
.days-future { color: var(--color-text-muted); }

.status-pill {
  display: inline-block;
  padding: 3px 9px;
  border-radius: 10px;
  font-size: 11px;
  font-weight: 600;
}

.status-paid { background: var(--color-success-bg); color: var(--color-success); }
.status-partial { background: var(--color-warning-bg); color: var(--color-warning); }
.status-overdue { background: var(--color-danger-bg); color: var(--color-danger); }
.status-sent { background: #eff6ff; color: #2563eb; }
.status-draft { background: var(--color-surface-alt); color: var(--color-text-muted); }

.notes-input {
  width: 100%;
  padding: 5px 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-family: inherit;
  min-height: 32px;
  resize: vertical;
  background: var(--color-surface);
}

.notes-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-light);
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 5px 10px;
  border: 1px solid var(--color-border-strong);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  color: var(--color-text);
  font-family: inherit;
  white-space: nowrap;
}

.btn-action:hover { background: var(--color-surface-alt); }
.btn-action.success { color: var(--color-success); border-color: #a7f3d0; }
.btn-action.success:hover { background: var(--color-success-bg); }

.checkbox-wrap {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
}

.checkbox-wrap input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--color-primary);
}

/* ============ EMPTY / LOADING ============ */
.empty-state, .loading-state {
  padding: 60px 20px;
  text-align: center;
  color: var(--color-text-muted);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  margin: 0 auto 12px;
  animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ============ MODAL ============ */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 20px;
  backdrop-filter: blur(2px);
}

.modal-content {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 30px;
  width: 100%;
  max-width: 440px;
  box-shadow: var(--shadow-lg);
  position: relative;
}

.modal-wide { max-width: 700px; }

.modal-content h2 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-text);
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  background: none;
  border: none;
  font-size: 24px;
  color: var(--color-text-muted);
  cursor: pointer;
  line-height: 1;
  width: 30px;
  height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
}

.modal-close:hover { background: var(--color-surface-alt); }

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  margin-top: 8px;
}

#password-form { display: flex; flex-direction: column; gap: 14px; }

/* ============ DETAIL VIEW ============ */
.detail-header { margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid var(--color-border); }
.detail-name { font-size: 22px; font-weight: 700; color: var(--color-text); margin-bottom: 4px; }
.detail-contact { color: var(--color-text-muted); font-size: 13px; }
.detail-section { margin-bottom: 18px; }
.detail-label { font-size: 11px; font-weight: 700; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 6px; }
.detail-value { font-size: 14px; color: var(--color-text); }
.detail-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  .topbar { padding: 10px 14px; }
  .parent-tabs, .sub-tabs, .search-bar, .table-wrapper { padding-left: 14px; padding-right: 14px; }
  .user-name { display: none; }
  .data-table { font-size: 12px; }
  .data-table th, .data-table td { padding: 8px 10px; }
  .detail-grid { grid-template-columns: 1fr; }
  .auth-card { padding: 28px 24px; }
}