/* Marine Species API - Main Stylesheet */

:root {
  /* Color Palette */
  --primary-blue: #2563eb;
  --success-green: #059669;
  --error-red: #dc2626;
  --warning-yellow: #d97706;
  
  /* Grays */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--gray-900);
  background-color: var(--gray-50);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Header */
.header {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.nav-icon {
  font-size: 1.5rem;
}

.nav-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-900);
}

.nav-tabs {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-tab {
  padding: var(--spacing-sm) var(--spacing-md);
  text-decoration: none;
  color: var(--gray-600);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
}

.nav-tab:hover {
  color: var(--primary-blue);
  background-color: var(--gray-100);
}

.nav-tab.active {
  color: var(--primary-blue);
  background-color: var(--gray-100);
}

/* Main Content */
.main {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

/* Footer */
.footer {
  background: white;
  border-top: 1px solid var(--gray-200);
  padding: var(--spacing-lg) 0;
  margin-top: auto;
}

.footer p {
  text-align: center;
  color: var(--gray-500);
  font-size: 0.875rem;
}

/* Typography */
h1 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: var(--spacing-lg);
}

h2 {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--gray-900);
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--gray-900);
  margin-bottom: var(--spacing-sm);
}

/* Cards */
.card {
  background: white;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  overflow: hidden;
  width: 100%;
}

.card-header {
  padding: 1.5rem;
  border-bottom: 1px solid #e5e7eb;
  background: #f9fafb;
}

.card-body {
  padding: 1.5rem;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
  margin: 0;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
  min-height: 44px;
}

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

.btn-primary:hover {
  background: #1d4ed8;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary:disabled {
  background: var(--gray-300);
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  background: white;
  color: var(--gray-700);
  border: 1px solid var(--gray-300);
}

.btn-secondary:hover {
  background: var(--gray-50);
  border-color: var(--gray-400);
}

/* Loading Spinner */
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid transparent;
  border-top: 2px solid currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .header .container {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .nav-tabs {
    gap: var(--spacing-md);
  }
  
  h1 {
    font-size: 1.75rem;
  }
  
  .main {
    padding: var(--spacing-lg) 0;
  }
}