/* Annotation Tool - Common Styles */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --text: #1f2937;
  --text-muted: #6b7280;
  --bg: #f9fafb;
  --white: #ffffff;
  --border: #e5e7eb;
  --error: #dc2626;
  --success: #16a34a;
  --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);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, 'Cantarell', 'Open Sans', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover {
  color: var(--primary-dark);
}

/* Header */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.95);
}

.site-header .site-logo {
  flex-shrink: 0;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  transition: transform 0.2s ease;
}

.site-logo:hover {
  transform: translateY(-1px);
}

.site-logo i {
  color: var(--primary);
  font-size: 1.375rem;
}

.site-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: flex-end;
  min-width: 0;
}

@media (min-width: 768px) {
  .site-nav {
    gap: 1.5rem;
  }
}

@media (min-width: 1024px) {
  .site-nav {
    gap: 2rem;
  }
}

.site-nav a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  padding: 0.25rem 0;
}

.site-nav a:not(.btn):hover {
  color: var(--primary);
}

.site-nav a:not(.btn)::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  transform: scaleX(0);
  transition: transform 0.2s ease;
}

.site-nav a:not(.btn):hover::after {
  transform: scaleX(1);
}

.site-nav .btn,
.site-nav .user-info {
  flex-shrink: 0;
}

/* Override nav link padding for buttons - .site-nav a has higher specificity */
.site-nav a.btn {
  padding: 0.625rem 1.25rem;
  color: var(--white);
}

.site-nav a.btn:hover {
  color: var(--white);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.625rem 1.25rem;
  border-radius: 0.5rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  font-size: 0.9375rem;
  transition: all 0.2s ease;
  text-decoration: none;
  white-space: nowrap;
}

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

.btn:active {
  transform: translateY(0);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: var(--white);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

.btn-lg {
  padding: 0.875rem 2rem;
  font-size: 1.0625rem;
}

/* Footer */
.site-footer {
  background: var(--white);
  border-top: 1px solid var(--border);
  padding: 2.5rem 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-top: auto;
}

.site-footer-mini {
  padding: 0.75rem 1rem;
  font-size: 0.8125rem;
}

.site-footer a {
  color: var(--text-muted);
  font-weight: 500;
}

.site-footer a:hover {
  color: var(--primary);
}

/* Form */
.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border);
  border-radius: 0.5rem;
  font-size: 0.9375rem;
  transition: all 0.2s ease;
  background: var(--white);
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-error {
  color: var(--error);
  font-size: 0.875rem;
  margin-top: 0.375rem;
  font-weight: 500;
}

.form-success {
  color: var(--success);
  font-size: 0.875rem;
  margin-top: 0.375rem;
  font-weight: 500;
}

/* Card */
.card {
  background: var(--white);
  border-radius: 1rem;
  box-shadow: var(--shadow-md);
  padding: 2rem;
  transition: all 0.3s ease;
  border: 1px solid transparent;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--border);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Utility Classes */
.text-center {
  text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

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

.fade-in {
  animation: fadeIn 0.5s ease;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.slide-up {
  animation: slideUp 0.6s ease;
}

/* Loading Spinner */
.spinner {
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 0.8s linear infinite;
  margin: 2rem auto;
}

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

/* Responsive */
@media (max-width: 768px) {
  .site-header {
    padding: 1rem;
  }
  
  .site-nav {
    gap: 1rem;
    font-size: 0.875rem;
  }
  
  .container {
    padding: 0 1rem;
  }
  
  .card {
    padding: 1.5rem;
  }
}