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

:root {
  --primary: #10b981;
  --primary-dark: #059669;
  --secondary: #3b82f6;
  --accent: #f59e0b;
  --danger: #ef4444;
  --dark: #1f2937;
  --gray: #6b7280;
  --light-gray: #f3f4f6;
  --white: #ffffff;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 100%);
  min-height: 100vh;
  color: var(--dark);
}

/* Header */
.header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  padding: 1rem 2rem;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--white);
  font-size: 1.5rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.3s ease;
}

.logo:hover {
  transform: scale(1.02);
}

.logo i {
  font-size: 2rem;
}

.nav {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  color: var(--white);
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  transition: all 0.3s ease;
  position: relative;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.15);
}

.nav-link.active {
  background: rgba(255, 255, 255, 0.2);
}

.user-menu {
  display: flex;
  align-items: center;
  gap: 1rem;
  color: var(--white);
}

.user-menu span {
  font-weight: 500;
}

.btn {
  padding: 0.625rem 1.25rem;
  border: none;
  border-radius: 0.5rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
}

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

.btn-primary:hover {
  background: var(--light-gray);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--white);
}

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

.btn-accent:hover {
  background: #d97706;
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

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

.btn-danger:hover {
  background: #dc2626;
}

/* Main Content */
.main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
  min-height: calc(100vh - 80px);
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, rgba(96, 285, 229, 0.2) 0%, rgba(59, 130, 246, 0.1) 100%), url('../images/beijing.png') center/cover no-repeat;
  border-radius: 1.5rem;
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
  height: 70vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.hero h1 {
  font-size: 3rem;
  color: var(--dark);
  margin-bottom: 1rem;
  font-weight: 800;
}

.hero p {
  font-size: 1.25rem;
  color: var(--gray);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary);
}

.stat-label {
  color: var(--gray);
  font-size: 0.9rem;
}

/* Category Section */
.category-section {
  margin-bottom: 3rem;
}

.category-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 3px solid var(--light-gray);
}

.category-header h2 {
  font-size: 1.5rem;
  color: var(--dark);
  font-weight: 700;
}

.category-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.category-health { background: linear-gradient(135deg, #10b981, #059669); color: white; }
.category-nutrition { background: linear-gradient(135deg, #f59e0b, #d97706); color: white; }
.category-mental { background: linear-gradient(135deg, #8b5cf6, #7c3aed); color: white; }

/* Posts Grid */
.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 1.5rem;
}

.post-card {
  background: var(--white);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  cursor: pointer;
}

.post-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.post-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.post-card:hover .post-image {
  transform: scale(1.05);
}

.post-content {
  padding: 1.25rem;
}

.post-category {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.post-category.health { background: #d1fae5; color: #065f46; }
.post-category.nutrition { background: #fef3c7; color: #92400e; }
.post-category.mental { background: #ede9fe; color: #5b21b6; }

.post-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 0.75rem;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-excerpt {
  color: var(--gray);
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--light-gray);
  font-size: 0.85rem;
  color: var(--gray);
}

.post-company {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 500;
}

.post-date {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

/* Post Detail Page */
.post-detail {
  background: var(--white);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.post-detail-header {
  position: relative;
  height: 400px;
}

.post-detail-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.post-detail-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
  padding: 3rem;
  color: var(--white);
}

.post-detail-category {
  display: inline-block;
  padding: 0.375rem 1rem;
  border-radius: 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.post-detail-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.post-detail-meta {
  display: flex;
  gap: 2rem;
  font-size: 0.95rem;
}

.post-detail-meta span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.post-detail-body {
  padding: 3rem;
}

.post-detail-content {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--dark);
  margin-bottom: 3rem;
}

.post-detail-content p {
  margin-bottom: 1.5rem;
}

.contact-info {
  background: var(--light-gray);
  border-radius: 1rem;
  padding: 2rem;
}

.contact-info h3 {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  color: var(--dark);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: var(--white);
  border-radius: 0.75rem;
}

.contact-item i {
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.contact-item div {
  flex: 1;
}

.contact-item label {
  font-size: 0.8rem;
  color: var(--gray);
  display: block;
}

.contact-item span {
  font-weight: 600;
  color: var(--dark);
}

.back-btn {
  margin-bottom: 2rem;
}

/* Auth Pages */
.auth-container {
  min-height: calc(100vh - 80px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.auth-card {
  background: var(--white);
  border-radius: 1.5rem;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 480px;
  overflow: hidden;
}

.auth-header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  padding: 2.5rem;
  text-align: center;
  color: var(--white);
}

.auth-header h2 {
  font-size: 1.75rem;
  margin-bottom: 0.5rem;
}

.auth-header p {
  opacity: 0.9;
}

.auth-body {
  padding: 2.5rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--dark);
  font-size: 0.9rem;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--light-gray);
  border-radius: 0.75rem;
  font-size: 1rem;
  transition: all 0.3s ease;
  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(16, 185, 129, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.auth-footer {
  text-align: center;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--light-gray);
}

.auth-footer a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
}

.auth-footer a:hover {
  text-decoration: underline;
}

.error-message {
  background: #fee2e2;
  color: #991b1b;
  padding: 0.875rem 1rem;
  border-radius: 0.5rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.success-message {
  background: #d1fae5;
  color: #065f46;
  padding: 0.875rem 1rem;
  border-radius: 0.5rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Checkbox Group */
.checkbox-group {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.checkbox-group input[type="checkbox"] {
  width: auto;
  margin-top: 0.25rem;
}

.checkbox-group label {
  font-weight: normal;
  font-size: 0.875rem;
  color: var(--gray);
}

.checkbox-group label a {
  color: var(--primary);
  text-decoration: none;
}

.checkbox-group label a:hover {
  text-decoration: underline;
}

/* Modal Styles */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  justify-content: center;
  align-items: center;
  z-index: 1000;
  padding: 1rem;
}

.modal-content {
  background: var(--white);
  border-radius: 1rem;
  max-width: 600px;
  width: 100%;
  max-height: 80vh;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  border-bottom: 1px solid var(--light-gray);
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: var(--white);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.25rem;
}

.modal-close {
  background: none;
  border: none;
  color: var(--white);
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0.8;
  transition: opacity 0.3s;
}

.modal-close:hover {
  opacity: 1;
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  max-height: 50vh;
}

.modal-body h3 {
  color: var(--dark);
  margin-bottom: 1rem;
}

.modal-body p {
  color: var(--gray);
  line-height: 1.8;
  margin-bottom: 0.75rem;
}

.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--light-gray);
  text-align: right;
}

/* Publish Page */
.publish-container {
  max-width: 800px;
  margin: 0 auto;
}

.publish-header {
  text-align: center;
  margin-bottom: 2rem;
}

.publish-header h1 {
  font-size: 2rem;
  color: var(--dark);
  margin-bottom: 0.5rem;
}

.publish-header p {
  color: var(--gray);
}

.publish-form {
  background: var(--white);
  border-radius: 1rem;
  padding: 2.5rem;
  box-shadow: var(--shadow);
}

.image-upload {
  border: 2px dashed var(--light-gray);
  border-radius: 1rem;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-bottom: 1.5rem;
}

.image-upload:hover {
  border-color: var(--primary);
  background: rgba(16, 185, 129, 0.05);
}

.image-upload i {
  font-size: 3rem;
  color: var(--gray);
  margin-bottom: 1rem;
}

.image-upload p {
  color: var(--gray);
}

.image-preview {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  border-radius: 0.75rem;
  margin-bottom: 1rem;
}

/* Footer */
.footer {
  background: var(--dark);
  color: var(--white);
  padding: 3rem 2rem 2rem;
  margin-top: 4rem;
}

.footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section h4 {
  font-size: 1.125rem;
  margin-bottom: 1rem;
}

.footer-section p,
.footer-section a {
  color: #9ca3af;
  text-decoration: none;
  line-height: 1.8;
}

.footer-section a:hover {
  color: var(--white);
}

.footer-bottom {
  max-width: 1400px;
  margin: 2rem auto 0;
  padding-top: 2rem;
  border-top: 1px solid #374151;
  text-align: center;
  color: #9ca3af;
}

/* Responsive */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 1rem;
  }

  .nav {
    gap: 1rem;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1.5rem;
  }

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

  .post-detail-header {
    height: 250px;
  }

  .post-detail-overlay {
    padding: 1.5rem;
  }

  .post-detail-title {
    font-size: 1.5rem;
  }

  .post-detail-body {
    padding: 1.5rem;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

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

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

/* Loading */
.loading {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 400px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--light-gray);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
}

.empty-state i {
  font-size: 4rem;
  color: var(--light-gray);
  margin-bottom: 1rem;
}

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

.empty-state p {
  color: var(--gray);
}