/* CSS Variables - Design System */
:root {
  /* Colors */
  --color-cream: #FDFBF7;
  --color-cream-dark: #F5F1E8;
  --color-warm-beige: #E8E0D5;
  --color-warm-black: #1A1614;
  --color-warm-gray: #6B635A;
  --color-terra: #D97757;
  --color-terra-dark: #C4623E;
  --color-amber: #C77D4E;

  /* Typography */
  --font-display: 'Fraunces', Georgia, serif;
  --font-sans: 'Commissioner', system-ui, sans-serif;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;

  /* Borders */
  --border-radius: 12px;
  --border-radius-sm: 8px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(26, 22, 20, 0.1);
  --shadow-md: 0 4px 6px rgba(26, 22, 20, 0.1);
  --shadow-lg: 0 10px 20px rgba(26, 22, 20, 0.15);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--color-cream);
  color: var(--color-warm-black);
  line-height: 1.6;
  min-height: 100vh;
}

img {
  max-width: 100%;
  display: block;
}

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

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

/* Navigation */
.navigation {
  background-color: white;
  border-bottom: 1px solid var(--color-warm-beige);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-warm-black);
  transition: color 0.2s;
}

.logo:hover {
  color: var(--color-terra);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--space-md);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--border-radius-sm);
  color: var(--color-warm-gray);
  font-weight: 600;
  transition: all 0.2s;
}

.nav-link:hover {
  background-color: var(--color-cream-dark);
  color: var(--color-warm-black);
}

.nav-link.active {
  background-color: var(--color-terra);
  color: white;
}

.nav-link svg {
  width: 20px;
  height: 20px;
}

/* Container */
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

/* Page Header */
.page-header {
  margin-bottom: var(--space-xl);
}

.page-title {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.page-subtitle {
  color: var(--color-warm-gray);
  font-size: 1.125rem;
}

/* Feed */
.feed {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

/* Post Card */
.post-card {
  background-color: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: transform 0.2s, box-shadow 0.2s;
}

.post-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.post-header {
  padding: var(--space-sm) var(--space-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--color-cream-dark);
}

.post-username {
  font-weight: 700;
  color: var(--color-warm-black);
  transition: color 0.2s;
}

.post-username:hover {
  color: var(--color-terra);
}

.post-date {
  color: var(--color-warm-gray);
  font-size: 0.875rem;
}

.post-image-container {
  aspect-ratio: 1 / 1;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-cream-dark) 0%, var(--color-warm-beige) 100%);
  position: relative;
}

.post-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.4s ease;
}

.post-image.loaded {
  opacity: 1;
}

.post-caption {
  padding: var(--space-md);
  line-height: 1.5;
}

.caption-username {
  font-weight: 700;
  color: var(--color-warm-black);
  margin-right: var(--space-xs);
}

.caption-text {
  color: var(--color-warm-black);
}

/* Upload Form */
.upload-container {
  max-width: 500px;
  margin: 0 auto;
}

.upload-form {
  background-color: white;
  border-radius: var(--border-radius);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
}

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

.form-label {
  display: block;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--space-sm);
  border: 2px solid var(--color-warm-beige);
  border-radius: var(--border-radius-sm);
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-warm-black);
  background-color: var(--color-cream);
  transition: border-color 0.2s;
}

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

.form-textarea {
  resize: vertical;
  min-height: 80px;
}

.form-help {
  margin-top: var(--space-xs);
  font-size: 0.875rem;
  color: var(--color-warm-gray);
}

/* File Input */
.file-input-wrapper {
  position: relative;
}

.file-input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  overflow: hidden;
}

.file-input-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border: 2px dashed var(--color-warm-beige);
  border-radius: var(--border-radius-sm);
  background-color: var(--color-cream);
  cursor: pointer;
  transition: all 0.2s;
}

.file-input-label:hover {
  border-color: var(--color-terra);
  background-color: var(--color-cream-dark);
}

.file-input:focus + .file-input-label {
  border-color: var(--color-terra);
  box-shadow: 0 0 0 3px rgba(217, 119, 87, 0.1);
}

.file-input-label svg {
  color: var(--color-terra);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  border: none;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}

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

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

/* Alerts */
.alert {
  padding: var(--space-md);
  border-radius: var(--border-radius);
  margin-bottom: var(--space-lg);
  font-weight: 600;
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  animation: slideDown 0.3s ease;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

.alert-error {
  background-color: #FFF5F5;
  color: #C53030;
  border: 2px solid #FEB2B2;
}

.alert-success {
  background-color: #EFE;
  color: #373;
  border: 2px solid #CFC;
}

.alert-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
}

.alert-content {
  flex: 1;
}

.alert-title {
  font-weight: 700;
  margin-bottom: 4px;
}

.alert-message {
  font-weight: 500;
  font-size: 0.9375rem;
  line-height: 1.5;
}

.alert a {
  text-decoration: underline;
  color: inherit;
  font-weight: 700;
}

/* Profile */
.profile-header {
  background-color: white;
  border-radius: var(--border-radius);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
  box-shadow: var(--shadow-md);
}

.profile-username {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.profile-meta {
  color: var(--color-warm-gray);
  font-size: 1rem;
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

/* Photo Grid */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.photo-grid-item {
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: var(--border-radius-sm);
  background: linear-gradient(135deg, var(--color-cream-dark) 0%, var(--color-warm-beige) 100%);
  position: relative;
  cursor: pointer;
  transition: transform 0.2s;
}

.photo-grid-item:hover {
  transform: scale(1.05);
}

.photo-grid-item:hover .photo-grid-overlay {
  opacity: 1;
}

.photo-grid-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.4s ease;
}

.photo-grid-image.loaded {
  opacity: 1;
}

.photo-grid-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(26, 22, 20, 0.8);
  color: white;
  padding: var(--space-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  opacity: 0;
  transition: opacity 0.2s;
}

.photo-grid-overlay p {
  font-size: 0.875rem;
  line-height: 1.4;
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: var(--space-xl);
  color: var(--color-warm-gray);
}

.empty-state p {
  font-size: 1.125rem;
}

/* Error Page */
.error-container {
  text-align: center;
  padding: var(--space-xl);
}

.error-title {
  font-family: var(--font-display);
  font-size: 3rem;
  color: var(--color-terra);
  margin-bottom: var(--space-md);
}

.error-message {
  font-size: 1.25rem;
  color: var(--color-warm-gray);
  margin-bottom: var(--space-xl);
}

/* Authentication Pages */
.auth-wrapper {
  min-height: calc(100vh - 80px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
}

.auth-card {
  background-color: white;
  border-radius: var(--border-radius);
  padding: var(--space-xl);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 400px;
}

.auth-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.auth-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.auth-subtitle {
  color: var(--color-warm-gray);
  font-size: 1rem;
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.auth-form .form-group {
  margin-bottom: 0;
}

.auth-form .btn-primary {
  width: 100%;
  margin-top: var(--space-sm);
}

.auth-divider {
  text-align: center;
  color: var(--color-warm-gray);
  margin: var(--space-lg) 0;
  position: relative;
}

.auth-divider::before,
.auth-divider::after {
  content: '';
  position: absolute;
  top: 50%;
  width: 40%;
  height: 1px;
  background-color: var(--color-warm-beige);
}

.auth-divider::before {
  left: 0;
}

.auth-divider::after {
  right: 0;
}

.auth-link {
  text-align: center;
  color: var(--color-warm-gray);
  font-size: 0.9375rem;
}

.auth-link a {
  color: var(--color-terra);
  font-weight: 600;
}

.auth-link a:hover {
  color: var(--color-terra-dark);
  text-decoration: underline;
}

/* User navigation */
.nav-user {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.nav-username {
  color: var(--color-warm-black);
  font-weight: 600;
}

.btn-logout {
  background: none;
  border: 1px solid var(--color-warm-beige);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--border-radius-sm);
  color: var(--color-warm-gray);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-logout:hover {
  background-color: var(--color-cream-dark);
  border-color: var(--color-terra);
  color: var(--color-terra);
}

/* Pagination */
.pagination-container {
  margin-top: var(--space-xl);
  margin-bottom: var(--space-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

.btn-load-more {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  background-color: white;
  border: 2px solid var(--color-warm-beige);
  border-radius: var(--border-radius);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-warm-black);
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.btn-load-more:hover {
  border-color: var(--color-terra);
  background-color: var(--color-cream);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-load-more svg {
  transition: transform 0.3s ease;
  color: var(--color-terra);
}

.btn-load-more:hover svg {
  transform: translateY(2px);
}

.btn-load-more.loading {
  pointer-events: none;
  opacity: 0.6;
}

.pagination-meta {
  color: var(--color-warm-gray);
  font-size: 0.875rem;
  text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
  .page-title {
    font-size: 2rem;
  }

  .nav-link span {
    display: none;
  }

  .photo-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .upload-form {
    padding: var(--space-lg);
  }
}

@media (max-width: 480px) {
  .nav-container {
    padding: var(--space-sm);
  }

  .container {
    padding: var(--space-md) var(--space-sm);
  }

  .page-title {
    font-size: 1.75rem;
  }

  .logo {
    font-size: 1.5rem;
  }
}

/* =============================================
   EXPLORE PAGE STYLES
   ============================================= */

/* Explore Header - Sticky */
.explore-header {
  background-color: white;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(26, 22, 20, 0.08);
  height: 60px;
}

.explore-header-container {
  max-width: 935px;
  margin: 0 auto;
  padding: 0 var(--space-md);
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.explore-logo {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-warm-black);
  transition: color 0.2s;
}

.explore-logo:hover {
  color: var(--color-terra);
}

.explore-header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.btn-signup-cta {
  display: inline-block;
  background-color: var(--color-terra);
  color: white;
  padding: 0.5rem 1.25rem;
  border-radius: 20px;
  font-weight: 600;
  font-size: 0.9375rem;
  box-shadow: 0 2px 8px rgba(217, 119, 87, 0.3);
  transition: all 0.2s;
}

.btn-signup-cta:hover {
  background-color: var(--color-terra-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(217, 119, 87, 0.4);
}

.btn-login {
  color: var(--color-warm-gray);
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 0.5rem 1rem;
  transition: color 0.2s;
}

.btn-login:hover {
  color: var(--color-warm-black);
}

/* Explore Main */
.explore-main {
  max-width: 935px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

/* Explore Title Section */
.explore-title-section {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.explore-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.explore-subtitle {
  color: var(--color-warm-gray);
  font-size: 1rem;
}

/* Explore Grid - 3 columns, 4px gap */
.explore-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
}

.explore-grid-item {
  aspect-ratio: 1 / 1;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-cream-dark) 0%, var(--color-warm-beige) 100%);
  cursor: pointer;
  opacity: 0;
  animation: fadeInUp 0.4s ease forwards;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.explore-grid-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.4s ease, transform 0.3s ease;
}

.explore-grid-image.loaded {
  opacity: 1;
}

.explore-grid-item:hover .explore-grid-image {
  transform: scale(1.05);
}

.explore-grid-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(26, 22, 20, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.explore-grid-item:hover .explore-grid-overlay {
  opacity: 1;
}

.explore-grid-username {
  color: white;
  font-weight: 600;
  font-size: 0.875rem;
}

/* Explore Empty State */
.explore-empty-state {
  text-align: center;
  padding: var(--space-xl) var(--space-md);
  max-width: 400px;
  margin: var(--space-xl) auto;
}

.explore-empty-icon {
  margin-bottom: var(--space-lg);
}

.explore-empty-icon svg {
  color: var(--color-terra);
}

.explore-empty-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-warm-black);
  margin-bottom: var(--space-xs);
}

.explore-empty-text {
  color: var(--color-warm-gray);
  font-size: 1rem;
  margin-bottom: var(--space-lg);
}

.btn-signup-post {
  display: inline-block;
  background-color: var(--color-terra);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: 20px;
  font-weight: 600;
  font-size: 1rem;
  box-shadow: 0 2px 8px rgba(217, 119, 87, 0.3);
  transition: all 0.2s;
}

.btn-signup-post:hover {
  background-color: var(--color-terra-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(217, 119, 87, 0.4);
}

/* Photo View Page */
.photo-view-main {
  max-width: 935px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

.photo-view-container {
  background-color: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.photo-view-image-wrapper {
  width: 100%;
  background: linear-gradient(135deg, var(--color-cream-dark) 0%, var(--color-warm-beige) 100%);
}

.photo-view-image {
  width: 100%;
  height: auto;
  display: block;
  opacity: 0;
  transition: opacity 0.4s ease;
}

.photo-view-image.loaded {
  opacity: 1;
}

.photo-view-info {
  padding: var(--space-lg);
}

.photo-view-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-md);
}

.photo-view-username {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-warm-black);
  transition: color 0.2s;
}

.photo-view-username:hover {
  color: var(--color-terra);
}

.photo-view-date {
  color: var(--color-warm-gray);
  font-size: 0.875rem;
}

.photo-view-caption {
  color: var(--color-warm-black);
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: var(--space-lg);
}

.photo-view-actions {
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-warm-beige);
}

.btn-back-explore {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-warm-gray);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: color 0.2s;
}

.btn-back-explore:hover {
  color: var(--color-terra);
}

.photo-view-cta {
  text-align: center;
  margin-top: var(--space-xl);
  padding: var(--space-lg);
  background-color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-md);
}

.photo-view-cta p {
  color: var(--color-warm-gray);
  margin-bottom: var(--space-md);
}

/* Explore Page Responsive */
@media (max-width: 768px) {
  .explore-header {
    height: 52px;
  }

  .explore-grid {
    gap: 3px;
  }

  .explore-title {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .explore-main {
    padding: var(--space-md) 0;
  }

  .explore-title-section {
    padding: 0 var(--space-sm);
  }

  .explore-grid {
    gap: 2px;
  }

  .explore-header-container {
    padding: 0 var(--space-sm);
  }

  .photo-view-main {
    padding: var(--space-md) 0;
  }

  .photo-view-container {
    border-radius: 0;
  }

  .photo-view-cta {
    margin: var(--space-lg) var(--space-sm) 0;
  }
}