/* styles.css */

/* 1. Theme Variables */
:root {
    --color-primary:   #19764d;
    --color-secondary: #e6f7ee;
    --font-sans:       'Inter', sans-serif;
  }
  
  /* 2. Base Styles */
  * { box-sizing: border-box; }
  body {
    margin: 0;
    font-family: var(--font-sans), sans-serif;
    background: #f4f6f8;
    color: #333;
  }
  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
  }
  h1,h2,h3 { margin: 0; }
  
  /* 3. Hero */
  .hero {
    background: var(--color-primary);
    color: #fff;
    text-align: center;
    padding: 4rem 0;
  }
  .hero h1 {
    font-size: 2.5rem;
  }
  .hero p {
    font-size: 1.125rem;
    margin: 1rem 0 2rem;
  }
  .hero-nav {
    display: flex;
    justify-content: center;
    gap: 1rem;
  }
  .btn-primary {
    background: #fff;
    color: var(--color-primary);
    padding: .75rem 1.5rem;
    border-radius: .375rem;
    font-weight: 600;
    text-decoration: none;
    transition: transform .15s, box-shadow .15s;
  }
  .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  }
  
  /* 4. Feature Cards */
  .features {
    display: grid;
    gap: 2rem;
    padding: 4rem 0;
  }
  @media (min-width: 768px) {
    .features { grid-template-columns: repeat(2,1fr); }
  }
  .card {
    background: #fff;
    border-left: 4px solid var(--color-primary);
    border-radius: .5rem;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    transition: transform .2s, box-shadow .2s;
  }
  .card:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.1);
  }
  .card-content h2 {
    font-size: 1.5rem;
    margin-bottom: .5rem;
  }
  .btn-secondary {
    background: var(--color-secondary);
    color: var(--color-primary);
    padding: .5rem 1rem;
    border-radius: .375rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
    margin-top: 1rem;
  }
  
  /* 5. Unit Converters */
  .converters {
    background: #eaeff2;
    padding: 4rem 0;
  }
  .converters h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #0a0a0a;
    text-align: center;
  }
  .converter-grid {
    display: grid;
    gap: 1.5rem;
  }
  @media (min-width: 640px) {
    .converter-grid { grid-template-columns: repeat(2,1fr); }
  }
  @media (min-width: 1024px) {
    .converter-grid { grid-template-columns: repeat(4,1fr); }
  }
  .cat-card {
    background: #fff;
    border-radius: .5rem;
    padding: 1.5rem;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
  }
  .cat-card h3 {
    font-size: 1.25rem;
    margin-bottom: .75rem;
  }
  .cat-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
  }
  .cat-card li {
    margin-bottom: .5rem;
  }
  .cat-card a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color .2s;
  }
  .cat-card a:hover {
    text-decoration: underline;
  }
  
  /* 6. Footer */
  .site-footer {
    background: #fff;
    padding: 2rem 0;
    text-align: center;
    font-size: .875rem;
    color: #666;
  }
  .site-footer a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color .2s;
  }
  .site-footer a:hover {
    text-decoration: underline;
  }
  /* Small‐hero variant */
.hero.small {
    padding: 2rem 0;
  }
  
  /* Contact Form */
  .contact-form {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
  }
  
  .contact-form label {
    font-weight: 600;
    color: #0a0a0a;
  }
  
  .contact-form input,
  .contact-form textarea {
    padding: .75rem 1rem;
    border: 1px solid #ccc;
    border-radius: .375rem;
    font-size: 1rem;
    font-family: var(--font-sans);
    resize: vertical;
  }
  
  .contact-form button {
    align-self: flex-start;
    background: var(--color-primary);
    color: #fff;
    border: none;
    padding: .75rem 1.5rem;
    border-radius: .375rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity .2s, transform .2s;
  }
  
  .contact-form button:hover {
    opacity: .9;
    transform: translateY(-1px);
  }