:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #10b981;
    --dark: #1e293b;
    --light: #f8fafc;
    --easy: #22c55e;
    --medium: #eab308;
    --hard: #ef4444;
    --card-bg: #ffffff;
    --card-shadow: rgba(0, 0, 0, 0.1);
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", sans-serif;
  }
  
  body {
    background-color: var(--light);
    color: var(--dark);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
  }
  
  .container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    background-color: white;
    padding: 2.5rem;
    border-radius: 1rem;
    width: 100%;
    max-width: 800px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
  }
  
  header {
    text-align: center;
  }
  
  h1 {
    font-size: 2.5rem;
    color: var(--primary);
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
  }
  
  .subtitle {
    color: #64748b;
    font-size: 1rem;
  }
  
  .user-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }
  
  .user-container h3 {
    font-weight: 500;
    color: var(--dark);
  }
  
  .user-input-container {
    display: flex;
    gap: 0.75rem;
  }
  
  #user-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    border: 1px solid #cbd5e1;
    font-size: 1rem;
    transition: border-color 0.3s;
  }
  
  #user-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
  }
  
  #search-btn {
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    background-color: var(--primary);
    color: white;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 100px;
  }
  
  #search-btn:hover {
    background-color: var(--primary-dark);
  }
  
  #search-btn:active {
    transform: scale(0.98);
  }
  
  .loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
  }
  
  @keyframes spin {
    to {
      transform: rotate(360deg);
    }
  }
  
  .results-wrapper {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.5s, transform 0.5s;
  }
  
  .results-wrapper.hidden {
    display: none;
    opacity: 0;
    transform: translateY(20px);
  }
  
  .error-message {
    background-color: #fee2e2;
    color: #b91c1c;
    padding: 1rem;
    border-radius: 0.5rem;
    text-align: center;
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.5s, transform 0.5s;
  }
  
  .error-message.hidden {
    display: none;
    opacity: 0;
    transform: translateY(20px);
  }
  
  .stats-container {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
  }
  
  .progress {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 1.5rem;
  }
  
  .progress-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
  }
  
  .circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  }
  
  .circle::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: conic-gradient(var(--color) var(--progress), #e2e8f0 0);
    mask: radial-gradient(transparent 65%, black 66%);
    -webkit-mask: radial-gradient(transparent 65%, black 66%);
  }
  
  .easy-progress {
    --color: var(--easy);
    --progress: 0%;
  }
  
  .medium-progress {
    --color: var(--medium);
    --progress: 0%;
  }
  
  .hard-progress {
    --color: var(--hard);
    --progress: 0%;
  }
  
  .circle-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    width: 80%;
    height: 80%;
    border-radius: 50%;
    background-color: white;
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.05);
    z-index: 1;
  }
  
  .circle-inner span:first-child {
    font-weight: 600;
    font-size: 1.25rem;
    color: var(--dark);
  }
  
  .circle-inner .label {
    font-size: 0.875rem;
    color: #64748b;
  }
  
  .stats-card-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
  }
  
  .card {
    background-color: var(--card-bg);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: transform 0.3s, box-shadow 0.3s;
    animation: fadeIn 0.5s ease-out forwards;
    opacity: 0;
  }
  
  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
  }
  
  .card h4 {
    color: #64748b;
    font-size: 0.875rem;
    font-weight: 500;
  }
  
  .card p {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark);
  }
  
  footer {
    text-align: center;
    color: #64748b;
    font-size: 0.875rem;
    margin-top: 1rem;
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  @keyframes progressAnimation {
    from {
      --progress: 0%;
    }
  }
  
  @media (max-width: 768px) {
    .container {
      padding: 1.5rem;
    }
  
    .circle {
      width: 120px;
      height: 120px;
    }
  
    .progress {
      gap: 1rem;
    }
  }
  
  @media (max-width: 480px) {
    .user-input-container {
      flex-direction: column;
    }
  
    #search-btn {
      width: 100%;
    }
  
    .circle {
      width: 100px;
      height: 100px;
    }
  
    .circle-inner span:first-child {
      font-size: 1rem;
    }
  
    .circle-inner .label {
      font-size: 0.75rem;
    }
  }