/* CSS Variables */
:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-light: #eff6ff;
  --border: #e2e8f0;
  --shadow: rgba(0, 0, 0, 0.1);
  --tag-bg: #f1f5f9;
  --tag-text: #475569;
  --success: #10b981;
  --error: #ef4444;
  --gradient-start: #1e3a5f;
  --gradient-end: #3b82f6;
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #60a5fa;
  --accent-hover: #3b82f6;
  --accent-light: #1e3a5f;
  --border: #334155;
  --shadow: rgba(0, 0, 0, 0.3);
  --tag-bg: #334155;
  --tag-text: #cbd5e1;
  --gradient-start: #1e3a5f;
  --gradient-end: #2563eb;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

/* Progress Bar */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--border);
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.3s;
}

.progress-bar.active {
  opacity: 1;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover));
  width: 0%;
  transition: width 0.1s ease-out;
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 100px;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4));
  animation: shimmer 1s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100px); }
  100% { transform: translateX(100px); }
}

/* Theme Toggle */
.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  display: flex;
  gap: 0.25rem;
  background: var(--bg-card);
  padding: 0.25rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px var(--shadow);
  z-index: 100;
}

.theme-btn {
  background: transparent;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  border-radius: 6px;
  font-size: 1rem;
  opacity: 0.6;
  transition: all 0.2s;
}

.theme-btn:hover,
.theme-btn.active {
  background: var(--accent-light);
  opacity: 1;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
  padding: 1.5rem 2rem;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  border-radius: 16px;
  color: white;
}

.logo {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-icon {
  width: 60px;
  height: 60px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 1.5rem;
}

.header h1 {
  font-size: 2rem;
  margin-bottom: 0.25rem;
}

.tagline {
  opacity: 0.9;
  font-size: 1rem;
}

/* Controls */
.controls {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
}

.search-box {
  flex: 1;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  background: var(--bg-card);
  color: var(--text-primary);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.filter-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-tag {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.875rem;
  transition: all 0.2s;
}

.filter-tag:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.filter-tag.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

/* Project Card */
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px var(--shadow);
}

.project-card.featured {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent);
}

.project-image {
  height: 160px;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 3rem;
}

.project-content {
  padding: 1.25rem;
}

.project-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.featured-badge {
  background: var(--accent);
  color: white;
  font-size: 0.65rem;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  font-weight: 500;
}

.project-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  line-height: 1.5;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.project-tag {
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 500;
}

.project-links {
  display: flex;
  gap: 0.75rem;
}

.project-link {
  flex: 1;
  padding: 0.5rem;
  border-radius: 6px;
  text-align: center;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s;
}

.project-link.live {
  background: var(--accent);
  color: white;
}

.project-link.live:hover {
  background: var(--accent-hover);
}

.project-link.github {
  background: var(--tag-bg);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.project-link.github:hover {
  background: var(--border);
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 1rem;
}

.modal.active {
  display: flex;
}

.modal-content {
  background: var(--bg-card);
  border-radius: 12px;
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 1.25rem;
}

.close-btn {
  background: transparent;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0.25rem 0.5rem;
}

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

#addProjectForm {
  padding: 1.25rem;
}

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

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: flex-end;
  margin-top: 1.5rem;
}

/* Buttons */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

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

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

.btn-secondary {
  background: var(--tag-bg);
  color: var(--text-primary);
}

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

.btn-small {
  padding: 0.5rem 0.75rem;
  font-size: 0.8rem;
  margin-top: 0.5rem;
}

/* Auth Navigation */
.nav-auth {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.auth-logged-out,
.auth-logged-in {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.auth-logged-in {
  display: none;
}

.user-greeting {
  font-size: 0.9rem;
  opacity: 0.9;
}

.nav-auth .btn {
  margin-top: 0;
  white-space: nowrap;
}

.nav-auth .btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
  color: white;
}

.nav-auth .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.3);
}

.nav-auth .btn-primary {
  background: white;
  color: var(--gradient-start);
}

.nav-auth .btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
}

/* Toast Notifications */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  color: white;
  font-weight: 500;
  z-index: 10000;
  opacity: 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
  box-shadow: 0 4px 12px var(--shadow);
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.toast-success {
  background: var(--success);
}

.toast-error {
  background: var(--error);
}

/* FAB */
.fab {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  box-shadow: 0 4px 12px var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  z-index: 100;
}

.fab:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 20px var(--shadow);
}

/* Footer */
.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.footer-small {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

/* Loading Overlay */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 300;
  color: white;
}

.loading-overlay.active {
  display: flex;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 1rem;
}

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

/* Empty State */
.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-secondary);
}

.empty-state h3 {
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

/* Responsive */
@media (min-width: 640px) {
  .controls {
    flex-direction: row;
    align-items: center;
  }

  .search-box {
    max-width: 300px;
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 1.5rem;
  }

  .projects-grid {
    grid-template-columns: 1fr;
  }

  .logo {
    flex-direction: column;
    text-align: center;
  }
}