:root {
    --primary: hsl(172, 67%, 45%);
    --dark-cyan: hsl(183, 100%, 15%);
    --dark-gray-cyan: hsl(186, 14%, 43%);
    --gray-cyan: hsl(184, 14%, 56%);
    --light-gray-cyan: hsl(185, 41%, 84%);
    --very-light-cyan: hsl(189, 41%, 97%);
    --white: hsl(0, 0%, 100%);
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Space Mono', monospace;
  }
  
  body {
    background: hsl(185, 41%, 84%);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
    min-height: 100vh;
  }
  
  h1 {
    color: hsl(183, 100%, 15%);
    letter-spacing: 5px;
    text-align: center;
    margin-bottom: 40px;
  }
  
  .container {
    background: white;
    border-radius: 20px;
    padding: 30px;
    max-width: 800px;
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 30px;
  }
  
  .calculator {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
  }
  
  .inputs, .results {
    flex: 1;
    min-width: 300px;
  }
  
  label {
    display: block;
    margin-bottom: 8px;
    color: hsl(186, 14%, 43%);
    font-weight: bold;
  }
  
  input[type="number"] {
    width: 100%;
    padding: 10px;
    border: none;
    background: hsl(189, 41%, 97%);
    border-radius: 5px;
    font-size: 1.2rem;
    margin-bottom: 20px;
    text-align: right;
  }
  
  input::placeholder {
    color: hsl(186, 14%, 43%);
  }
  
  .tip-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 20px;
  }
  
  .tip, #custom-tip {
    background: hsl(183, 100%, 15%);
    color: white;
    border: none;
    padding: 10px;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
  }
  
  .tip:hover {
    background: hsl(172, 67%, 45%);
  }
  
  #custom-tip {
    background: hsl(189, 41%, 97%);
    color: hsl(183, 100%, 15%);
    text-align: right;
  }
  
  .results {
    background: hsl(183, 100%, 15%);
    color: white;
    padding: 30px;
    border-radius: 15px;
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
  
  .result {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  .results {
    background: var(--dark-cyan);
    color: var(--white);
  }
  
  .result span {
    color: var(--gray-cyan);
  }
  
  #reset {
    background: var(--primary);
    color: var(--dark-cyan);
  }
  
  .result p {
    margin: 0;
  }
  
  .result span {
    font-size: 0.8rem;
    color: hsl(184, 14%, 56%);
  }
  
  #reset {
    background: hsl(172, 67%, 45%);
    color: hsl(183, 100%, 15%);
    font-weight: bold;
    border: none;
    padding: 15px;
    border-radius: 10px;
    margin-top: auto;
    cursor: pointer;
    font-size: 1rem;
  }
  
  #reset:hover {
    background: hsl(185, 41%, 84%);
  }

  .results {
    background: var(--dark-cyan);
    color: var(--white);
  }
  
  .result span {
    color: var(--gray-cyan);
  }
  
  #reset {
    background: var(--primary);
    color: var(--dark-cyan);
  }
  
  body {
    background: var(--light-gray-cyan);
    color: var(--dark-gray-cyan);
  }
  
  input[type="number"],
  #custom-tip {
    background: var(--very-light-cyan);
    color: var(--dark-cyan);
  }
  
  .tip {
    background: var(--dark-cyan);
    color: var(--white);
  }
  
  .tip:hover,
  #reset:hover {
    background: var(--primary);
    color: var(--dark-cyan);
  }