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

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background:  #0b0f1a;
  color: #e0e0e0;
  min-height: 100vh;
}

/* Header */
.header {
  background: linear-gradient(90deg, #0f172a 0%, #1a2847 100%);
  border-bottom: 1px solid rgba(0, 217, 255, 0.2);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.header-container img {
  width: 150px;
  color:  #0b0f1a;
}


.logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: #00d9ff;
}

.logo-text {
  background: linear-gradient(90deg, #00d9ff, #00ff88);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  gap: 2rem;
}

.nav-link {
  color: #e0e0e0;
  text-decoration: none;
  transition: color 0.3s;
}

.nav-link:hover {
  color: #00d9ff;
}

.sign-in-btn {
  background-color: #1a2847;
  color: #a8ff60;
  border: 1px solid #a8ff60;
  padding: 0.5rem 1.5rem;
  border-radius: 9px;
  cursor: pointer;
  height: 42px;
  transition: all 0.3s;
  font-weight: 900;
  
}

.sign-in-btn:hover {
  background: #00d9ff;
  color: #0f172a;
}

/* Explore Container */
.explore-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 2rem;
}

/* Sidebar */
.sidebar {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(0, 217, 255, 0.2);
  border-radius: 8px;
  padding: 1.5rem;
  height: fit-content;
  position: sticky;
  top: 80px;
}

.filter-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(0, 217, 255, 0.2);
}

.filter-header h2 {
  font-size: 1.25rem;
  color: #ffffff;
}

.clear-all-btn {
  background: none;
  border: none;
  color: #00d9ff;
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: bold;
  transition: color 0.3s;
}

.clear-all-btn:hover {
  color: #00ff88;
}

.filter-section {
  margin-bottom: 1.5rem;
}

.filter-title {
  font-size: 0.85rem;
  font-weight: bold;
  color: #00d9ff;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.filter-header-topic {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.view-all {
  color: #00d9ff;
  cursor: pointer;
  font-size: 0.8rem;
  transition: color 0.3s;
}

.view-all:hover {
  color: #00ff88;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.filter-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 4px;
  transition: background 0.3s;
}

.filter-item:hover {
  background: rgba(0, 217, 255, 0.1);
}

.filter-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: #00d9ff;
}

.filter-item span {
  font-size: 0.95rem;
}

/* Main Content */
.main-content {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(0, 217, 255, 0.2);
  border-radius: 8px;
  padding: 2rem;
}

.content-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
  height: 5px;
}

.header-left h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  color: #a0a0a0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto,
       Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  
}

.problem-count {
  font-size: 0.95rem;
  color: #a0a0a0;
}

.header-right-controls {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.search-box {
  position: relative;
  width: 250px;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1rem;
  background: rgba(0, 217, 255, 0.1);
  border: 1px solid rgba(0, 217, 255, 0.3);
  border-radius: 4px;
  color: #ffffff;
  font-size: 0.95rem;
}

.search-input::placeholder {
  color: #707070;
}

.search-input:focus {
  outline: none;
  border-color: #00d9ff;
  background: rgba(0, 217, 255, 0.15);
}

.search-icon {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: #707070;
}

.sort-dropdown {
  padding: 0.75rem 1rem;
  background: rgba(0, 217, 255, 0.1);
  border: 1px solid rgba(0, 217, 255, 0.3);
  border-radius: 4px;
  color: #00d9ff;
  cursor: pointer;
  transition: all 0.3s;
}

.sort-dropdown:hover,
.sort-dropdown:focus {
  border-color: #00d9ff;
  background: rgba(0, 217, 255, 0.15);
}

/* Active Filters */
.active-filters {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
  min-height: 30px;
}

.filter-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(0, 217, 255, 0.2);
  color: #00d9ff;
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  font-size: 0.85rem;
}

.filter-tag button {
  background: none;
  border: none;
  color: #00d9ff;
  cursor: pointer;
  font-size: 1rem;
  padding: 0;
}

/* Problems List */
.problems-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.problem-row {
  display: grid;
  grid-template-columns: 1fr auto auto auto auto;
  gap: 1rem;
  align-items: center;
  padding: 1.5rem;
  background: rgba(0, 217, 255, 0.05);
  border: 1px solid rgba(0, 217, 255, 0.1);
  border-radius: 8px;
  transition: all 0.3s;
}

.problem-row:hover {
  background: rgba(0, 217, 255, 0.1);
  border-color: rgba(0, 217, 255, 0.3);
}

.problem-info {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.problem-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  cursor: pointer;
  transition: color 0.3s;
}

.problem-title:hover {
  color: #00d9ff;
}

.problem-meta {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}

.company-tag {
  background: rgba(0, 217, 255, 0.15);
  color: #00d9ff;
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  font-size: 0.8rem;
}

.topic-tag {
  background: rgba(0, 255, 136, 0.15);
  color: #00ff88;
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  font-size: 0.8rem;
}

.problem-difficulty {
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 600;
}

.difficulty-easy {
  background: rgba(34, 197, 94, 0.2);
  color: #22c55e;
}

.difficulty-medium {
  background: rgba(234, 179, 8, 0.2);
  color: #eab308;
}

.difficulty-hard {
  background: rgba(239, 68, 68, 0.2);
  color: #ef4444;
}

.problem-stats {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.9rem;
  color: #a0a0a0;
}

.solve-btn {
  padding: 0.6rem 1.5rem;
  background: rgba(0, 217, 255, 0.2);
  color: #00d9ff;
  border: 1px solid #00d9ff;
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: all 0.3s;
  font-weight: 600;
  text-align: center;
}

.solve-btn:hover {
  background: #00d9ff;
  color: #0f172a;
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(0, 217, 255, 0.2);
}

.page-btn {
  padding: 0.6rem 1rem;
  background: rgba(0, 217, 255, 0.1);
  color: #00d9ff;
  border: 1px solid rgba(0, 217, 255, 0.3);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s;
}

.page-btn:hover {
  background: rgba(0, 217, 255, 0.2);
  border-color: #00d9ff;
}

.page-info {
  color: #a0a0a0;
  font-size: 0.95rem;
}

/* Footer */
.footer {
  background: linear-gradient(90deg, #0f172a 0%, #1a2847 100%);
  border-top: 1px solid rgba(0, 217, 255, 0.2);
  padding: 3rem 2rem 1rem;
  margin-top: 3rem;
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  color: #00d9ff;
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.footer-section a {
  display: block;
  color: #a0a0a0;
  text-decoration: none;
  margin-bottom: 0.75rem;
  transition: color 0.3s;
}

.footer-section a:hover {
  color: #00d9ff;
}

.footer-bottom {
  text-align: left;
  padding-top: 1rem;
  border-top: 1px solid rgba(0, 217, 255, 0.2);
  color: #707070;
  font-size: 0.9rem;
}
.footer-bottom .footer-links a{
  color: #707070;
  text-decoration: none;
  padding: 0.2%;

}

/* Responsive Design */
@media (max-width: 1024px) {
  .explore-container {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
  }

  .problem-row {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

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

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    gap: 1rem;
  }
  .header-right-controls {
    display: none;
  }

  .nav-menu {
    gap: 1rem;
    font-size: 0.9rem;
  }
  .header-right{
    display: none;
  }

  .content-header {
    flex-direction: column;
  }

  .header-right-controls {
    flex-direction: column;
    width: 100%;
  }

  .search-box {
    width: 100%;
  }

  .problem-row {
    padding: 1rem;
  }

  .pagination {
    flex-direction: column;
    gap: 0.75rem;
  }

  .footer-container {
    grid-template-columns: 1fr;
  }
}