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

:root {
  --primary-color: #3b82f6;
  --secondary-color: #10b981;
  --danger-color: #ef4444;
  --background: #f9fafb;
  --surface: #ffffff;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --border: #e5e7eb;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem;
}

/* Header */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  margin-bottom: 2rem;
}

.header h1 {
  font-size: 1.5rem;
  font-weight: 600;
}

.header .sync-status {
  display: inline-block;
  margin-left: 1rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.header .sync-status.synced {
  color: var(--secondary-color);
}

.header .sync-status.unsynced {
  color: var(--danger-color);
}

/* Buttons */
.button-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.tracker-button {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: 0.5rem;
  padding: 1.5rem 1rem;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  text-align: center;
}

.tracker-button:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.tracker-button:active {
  transform: translateY(0);
}

.tracker-button img {
  width: 64px;
  height: 64px;
  object-fit: contain;
}

.tracker-button .label {
  font-weight: 500;
  font-size: 1rem;
}

/* Form elements */
input[type="password"],
input[type="text"] {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  font-size: 1rem;
}

button[type="submit"],
.btn {
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 0.375rem;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

button[type="submit"]:hover,
.btn:hover {
  background: #2563eb;
}

.btn-secondary {
  background: var(--text-secondary);
}

.btn-secondary:hover {
  background: #4b5563;
}

.btn-danger {
  background: var(--danger-color);
}

.btn-danger:hover {
  background: #dc2626;
}

/* Login page */
.login-container {
  max-width: 400px;
  margin: 4rem auto;
  padding: 2rem;
  background: var(--surface);
  border-radius: 0.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.login-container h1 {
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.error-message {
  color: var(--danger-color);
  font-size: 0.875rem;
  margin-top: 0.5rem;
}

/* Stats table */
.stats-container {
  background: var(--surface);
  border-radius: 0.5rem;
  padding: 1.5rem;
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

thead {
  background: var(--background);
}

th,
td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-transform: uppercase;
}

tr:hover {
  background: var(--background);
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 500;
}

.badge-success {
  background: #d1fae5;
  color: #065f46;
}

.badge-warning {
  background: #fef3c7;
  color: #92400e;
}

/* Utility classes */
.mt-1 {
  margin-top: 0.5rem;
}
.mt-2 {
  margin-top: 1rem;
}
.mb-1 {
  margin-bottom: 0.5rem;
}
.mb-2 {
  margin-bottom: 1rem;
}

.text-center {
  text-align: center;
}

.hidden {
  display: none;
}

/* Loading spinner */
.spinner {
  border: 3px solid var(--border);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  width: 24px;
  height: 24px;
  animation: spin 1s linear infinite;
  display: inline-block;
  margin-left: 0.5rem;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}