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

:root {
  --primary: #10B981;
  --primary-dark: #059669;
  --secondary: #F59E0B;
  --dark: #1F2937;
  --light: #F3F4F6;
  --white: #FFFFFF;
}

body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  background: var(--light);
  min-height: 100vh;
}

/* Header */
.social-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.back-btn {
  color: var(--white);
  text-decoration: none;
  font-size: 1.2rem;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: background 0.3s;
}

.back-btn:hover {
  background: rgba(255,255,255,0.2);
}

.header-title {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
}

.header-name {
  font-weight: 700;
  font-size: 1.2rem;
}

.header-number {
  background: var(--secondary);
  padding: 4px 12px;
  border-radius: 6px;
  font-weight: 800;
}

.user-menu {
  position: relative;
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--white);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  cursor: pointer;
}

.user-dropdown {
  display: none;
  position: absolute;
  top: 50px;
  right: 0;
  background: var(--white);
  border-radius: 12px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.15);
  min-width: 200px;
  overflow: hidden;
}

.user-dropdown.show { display: block; }

.user-info {
  padding: 15px;
  border-bottom: 1px solid var(--light);
}

.user-name { font-weight: 600; }
.user-email { font-size: 0.85rem; color: #666; }

.user-dropdown button {
  width: 100%;
  padding: 15px;
  border: none;
  background: none;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  transition: background 0.3s;
}

.user-dropdown button:hover {
  background: var(--light);
}

/* Navigation */
.social-nav {
  position: fixed;
  top: 60px;
  left: 0;
  right: 0;
  height: 50px;
  background: var(--white);
  display: flex;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
  z-index: 999;
}

.nav-item {
  flex: 1;
  border: none;
  background: none;
  padding: 10px;
  font-size: 0.85rem;
  color: #666;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.nav-item.active {
  color: var(--primary);
  border-bottom: 3px solid var(--primary);
  font-weight: 600;
}

@media (max-width: 768px) {
  .social-nav { display: none; }
}

/* Main Content */
.social-main {
  padding: 130px 20px 100px;
  max-width: 800px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .social-main { padding: 80px 15px 100px; }
}

.content-section { display: none; }
.content-section.active { display: block; }

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

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

.new-post-btn {
  background: var(--primary);
  color: var(--white);
  border: none;
  padding: 10px 20px;
  border-radius: 25px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: transform 0.3s;
}

.new-post-btn:hover { transform: scale(1.05); }

/* Tabs */
.tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  overflow-x: auto;
  padding-bottom: 5px;
}

.tab-btn {
  background: var(--white);
  border: none;
  padding: 10px 20px;
  border-radius: 25px;
  font-size: 0.9rem;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.3s;
}

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

/* Posts */
.post-card {
  background: var(--white);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 15px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.post-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 15px;
}

.post-avatar {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.post-author-info { flex: 1; }
.post-author { font-weight: 600; }
.post-time { font-size: 0.8rem; color: #888; }

.post-category {
  padding: 4px 12px;
  border-radius: 15px;
  font-size: 0.75rem;
  font-weight: 500;
}

.post-title {
  font-size: 1.1rem;
  margin-bottom: 10px;
  color: var(--dark);
}

.post-content {
  color: #555;
  margin-bottom: 15px;
  line-height: 1.6;
}

.post-actions {
  display: flex;
  gap: 20px;
  padding-top: 15px;
  border-top: 1px solid var(--light);
}

.post-action {
  background: none;
  border: none;
  color: #666;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.9rem;
  transition: color 0.3s;
}

.post-action:hover { color: var(--primary); }
.post-action.liked { color: #EF4444; }

/* Events */
.event-card {
  background: var(--white);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 15px;
  display: flex;
  align-items: center;
  gap: 20px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.event-date {
  text-align: center;
  padding: 15px;
  background: var(--primary);
  color: var(--white);
  border-radius: 12px;
  min-width: 80px;
}

.event-day { display: block; font-weight: 700; }
.event-time { font-size: 0.85rem; opacity: 0.9; }

.event-info { flex: 1; }
.event-info h4 { margin-bottom: 5px; }
.event-info p { font-size: 0.9rem; color: #666; }

.event-action {
  background: var(--light);
  border: none;
  padding: 10px 20px;
  border-radius: 25px;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.3s;
}

.event-action.participating {
  background: var(--primary);
  color: var(--white);
}

/* Conversations */
.conversation-item {
  background: var(--white);
  padding: 15px 20px;
  display: flex;
  align-items: center;
  gap: 15px;
  border-bottom: 1px solid var(--light);
  cursor: pointer;
  transition: background 0.3s;
}

.conversation-item:first-child { border-radius: 16px 16px 0 0; }
.conversation-item:last-child { border-radius: 0 0 16px 16px; border: none; }
.conversation-item:hover { background: var(--light); }

.conversation-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.conversation-info { flex: 1; }
.conversation-name { font-weight: 600; }
.conversation-preview { font-size: 0.85rem; color: #666; }

.conversation-meta { text-align: right; }
.conversation-time { font-size: 0.75rem; color: #888; }

.conversation-badge {
  background: var(--primary);
  color: var(--white);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* Profile */
.profile-card {
  background: var(--white);
  border-radius: 20px;
  padding: 30px;
  text-align: center;
  margin-bottom: 20px;
}

.profile-avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin: 0 auto 15px;
}

.profile-member {
  color: #888;
  margin-bottom: 20px;
}

.profile-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
}

.stat-item { text-align: center; }
.stat-value { display: block; font-size: 1.5rem; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 0.85rem; color: #666; }

/* Ranking */
.ranking-card {
  background: var(--white);
  border-radius: 20px;
  padding: 20px;
}

.ranking-card h3 {
  margin-bottom: 15px;
  padding-bottom: 15px;
  border-bottom: 1px solid var(--light);
}

.ranking-item {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 12px 0;
  border-bottom: 1px solid var(--light);
}

.ranking-item:last-child { border: none; }

.ranking-position {
  width: 30px;
  height: 30px;
  background: var(--light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.ranking-item:nth-child(1) .ranking-position { background: gold; color: var(--dark); }
.ranking-item:nth-child(2) .ranking-position { background: silver; color: var(--dark); }
.ranking-item:nth-child(3) .ranking-position { background: #CD7F32; color: var(--white); }

.ranking-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
}

.ranking-name { flex: 1; font-weight: 500; }
.ranking-points { color: var(--primary); font-weight: 600; }

/* Mobile Bottom Nav */
.mobile-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 70px;
  background: var(--white);
  box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
  z-index: 1000;
}

@media (max-width: 768px) {
  .mobile-bottom-nav {
    display: flex;
  }
}

.bottom-nav-item {
  flex: 1;
  border: none;
  background: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  color: #888;
  font-size: 0.7rem;
  cursor: pointer;
  transition: color 0.3s;
}

.bottom-nav-item i { font-size: 1.3rem; }
.bottom-nav-item.active { color: var(--primary); }

/* Modals */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal.show { display: flex; }

.modal-content {
  background: var(--white);
  border-radius: 20px;
  padding: 30px;
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.close-btn {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: #888;
}

.modal-content input,
.modal-content textarea,
.modal-content select {
  width: 100%;
  padding: 15px;
  border: 2px solid var(--light);
  border-radius: 12px;
  margin-bottom: 15px;
  font-size: 1rem;
  outline: none;
}

.modal-content input:focus,
.modal-content textarea:focus {
  border-color: var(--primary);
}

.modal-content textarea {
  min-height: 120px;
  resize: vertical;
}

.btn-primary {
  width: 100%;
  padding: 15px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.3s;
}

.btn-primary:hover { transform: scale(1.02); }

/* Login Modal */
.login-modal {
  text-align: center;
}

.login-modal h2 {
  color: var(--primary);
  margin-bottom: 10px;
}

.login-modal p {
  color: #666;
  margin-bottom: 30px;
}

.form-switch {
  margin-top: 20px;
  color: #666;
}

.form-switch a {
  color: var(--primary);
  cursor: pointer;
  font-weight: 600;
}

/* Comments */
.comments-modal {
  max-width: 600px;
}

.post-preview {
  padding: 15px;
  background: var(--light);
  border-radius: 12px;
  margin-bottom: 20px;
}

.post-preview h4 { margin-bottom: 5px; }
.post-preview p { font-size: 0.85rem; color: #666; }

.comments-list {
  max-height: 300px;
  overflow-y: auto;
  margin-bottom: 20px;
}

.comment-item {
  display: flex;
  gap: 12px;
  padding: 15px 0;
  border-bottom: 1px solid var(--light);
}

.comment-avatar {
  width: 35px;
  height: 35px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 600;
  flex-shrink: 0;
}

.comment-content {
  flex: 1;
  background: var(--light);
  padding: 12px 15px;
  border-radius: 15px;
}

.comment-author { font-weight: 600; font-size: 0.9rem; }
.comment-text { margin: 5px 0; }
.comment-time { font-size: 0.75rem; color: #888; }

.comment-input {
  display: flex;
  gap: 10px;
}

.comment-input input {
  flex: 1;
  margin: 0;
}

.comment-input button {
  width: 50px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 12px;
  cursor: pointer;
}