/* CSS Variables */
:root {
  --color-primary: #007bff;
  --color-primary-dark: #0056b3;
  --color-success: #28a745;
  --color-danger: #dc3545;
  --color-background: #f8f9fa;
  --color-card-bg: #ffffff;
  --color-text: #212529;
  --color-text-secondary: #6c757d;
  --color-border: #dee2e6;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --border-radius: 8px;
  --transition-speed: 0.2s;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-background);
}

/* App Container */
#app {
  min-height: 100vh;
  padding: var(--spacing-md);
}

/* View Containers */
.view {
  max-width: 100%;
  margin: 0 auto;
}

/* Typography */
h1 {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text);
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

p {
  margin-bottom: var(--spacing-sm);
}

/* Buttons */
button,
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-speed) ease;
  min-height: 44px;
  min-width: 44px;
}

button:focus,
.btn:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

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

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

.btn-secondary:hover {
  background-color: #5a6268;
  border-color: #545b62;
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

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

/* Date Navigation */
.date-navigation {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  padding: var(--spacing-md);
  background-color: var(--color-card-bg);
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.date-display {
  font-size: 1.25rem;
  font-weight: 600;
  text-align: center;
  padding: var(--spacing-sm) 0;
  color: var(--color-text);
}

.nav-buttons {
  display: flex;
  gap: var(--spacing-sm);
}

.nav-button {
  flex: 1;
  padding: 0.75rem;
  font-size: 1rem;
  min-height: 44px;
}

/* Settings Button */
.settings-button-container {
  margin-top: var(--spacing-lg);
  text-align: center;
}

/* Cards */
.card {
  background-color: var(--color-card-bg);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.shift-card {
  background-color: var(--color-card-bg);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  border: 2px solid var(--color-border);
}

.shift-card p {
  margin-bottom: var(--spacing-sm);
}

.shift-card p:last-child {
  margin-bottom: 0;
}

.shift-card strong {
  font-weight: 600;
  color: var(--color-text);
}

.tomorrow-indicator {
  color: var(--color-primary);
  font-weight: 600;
}

.no-shift {
  color: var(--color-text-secondary);
  font-style: italic;
  text-align: center;
  padding: var(--spacing-lg);
}

.overnight-end {
  background-color: #fff3cd;
  border-left: 4px solid #ffc107;
}

/* Forms */
label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 500;
  color: var(--color-text);
}

textarea {
  width: 100%;
  padding: var(--spacing-md);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  resize: vertical;
  min-height: 150px;
  background-color: var(--color-card-bg);
  color: var(--color-text);
}

textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

textarea[readonly] {
  background-color: #e9ecef;
  cursor: default;
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-actions {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.form-actions button {
  flex: 1;
}

/* Messages */
.message {
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  margin-bottom: var(--spacing-md);
}

.message-success {
  background-color: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.message-error {
  background-color: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

.message-info {
  background-color: #d1ecf1;
  color: #0c5460;
  border: 1px solid #bee5eb;
}

.error-list {
  margin: 0;
  padding-left: var(--spacing-lg);
}

.error-list li {
  margin-bottom: var(--spacing-xs);
}

/* Hidden */
.hidden {
  display: none !important;
}

/* Tablet and Desktop */
@media (min-width: 768px) {
  #app {
    padding: var(--spacing-xl);
  }

  .view {
    max-width: 600px;
  }

  .date-navigation {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .date-display {
    flex: 1;
    padding: 0;
  }

  .nav-button {
    flex: 0 0 auto;
    min-width: 120px;
  }

  textarea {
    min-height: 250px;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.75rem;
  }
}

/* Large Desktop */
@media (min-width: 1024px) {
  .view {
    max-width: 700px;
  }

  textarea {
    min-height: 300px;
  }
}

/* Animation */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card,
.shift-card {
  animation: fadeIn 0.3s ease;
}