:root {
  --primary-color: #4a90e2;
  --primary-hover: #357abd;
  --secondary-color: #6c757d;
  --secondary-hover: #5a6268;
  --bg-color: #f8f9fa;
  --text-main: #212529;
  --border-radius: 6px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-color);
  margin: 0;
  padding: 20px;
}

/* Flex Utilities */
.d-flex {
  display: flex;
}

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

.justify-center {
  justify-content: center;
}

.gap-sm {
  gap: var(--spacing-sm);
}

.gap-md {
  gap: var(--spacing-md);
}

.mt-md {
  margin-top: var(--spacing-md);
}

/* Form Elements */
input[type="text"],
input[type="datetime-local"] {
  padding: 8px 12px;
  border: 1px solid #ced4da;
  border-radius: var(--border-radius);
  font-size: 1rem;
}

label {
  font-weight: 500;
}

/* Modern Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  border: none;
  border-radius: var(--border-radius);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s, transform 0.1s;
  text-decoration: none;
  gap: 6px;
}

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

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

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

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

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

/* Icons */
.icon {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

/* Layout Specifics */
.control-row {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: var(--spacing-md);
  gap: var(--spacing-sm);
}

#stored-dates-container {
  max-width: 600px;
  margin: 20px auto;
  background: white;
  padding: 20px;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#stored-dates-list {
  list-style: none;
  padding: 0;
  text-align: left;
}

#stored-dates-list li {
  padding: 8px 0;
  border-bottom: 1px solid #eee;
}

#stored-dates-list li:last-child {
  border-bottom: none;
}

/* Mobile Responsiveness */
@media (max-width: 600px) {
  body {
    padding: 10px;
  }

  .control-row {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  /* Make inputs and buttons full width for easier touch */
  input[type="text"],
  input[type="datetime-local"],
  .btn {
    width: 100%;
    box-sizing: border-box;
    /* Ensure padding doesn't overflow width */
    font-size: 16px;
    /* Prevent iOS zoom on focus */
  }

  .btn {
    padding: 12px;
    /* Larger touch target */
    justify-content: center;
  }

  /* Adjust spacing for labels */
  .control-row label {
    margin-bottom: 4px;
    align-self: flex-start;
  }

  /* Reset some margins */
  #time,
  #date-label {
    margin: 0;
  }
}