/* ==========================================================================
   Spark Alliance - Main Stylesheet
   Edit variables below to change brand colours and spacing site-wide.
   ========================================================================== */

   :root {
    /* Brand colours - edit here for site-wide changes */
    --color-primary: #0d4f8b;
    --color-primary-dark: #083a6b;
    --color-accent: #f59e0b;
    --color-accent-hover: #d97706;
    --color-text: #1f2937;
    --color-text-muted: #6b7280;
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-border: #e5e7eb;
  
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-size-base: 1rem;
    --line-height-base: 1.6;
  
    /* Spacing - use for consistent section padding */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
  
    /* Layout */
    --container-max: 1200px;
    --header-height: 72px;
  }
  
  /* Reset & base */
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-bg);
  }
  
  img { max-width: 100%; height: auto; display: block; }
  a { color: var(--color-primary); text-decoration: none; }
  a:hover { text-decoration: underline; }
  
  /* Container - centres content and limits width */
  .container {
    width: 100%;
    max-width: var(--container-max);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--space-md);
    padding-right: var(--space-md);
  }
  
  /* ==========================================================================
     Header & Navigation - edit nav links in each HTML file
     ========================================================================== */
  .site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
  }
  
  .site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: var(--header-height);
  }
  
  .site-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-primary);
  }
  .site-logo img { height: 40px; width: auto; }
  
  .main-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    align-items: center;
  }
  
  .main-nav a {
    padding: var(--space-xs) var(--space-sm);
    color: var(--color-text);
    font-weight: 500;
    border-radius: 4px;
  }
  .main-nav a:hover {
    color: var(--color-primary);
    background: var(--color-bg-alt);
    text-decoration: none;
  }
  
  /* Mobile menu toggle - shown on small screens via JS */
  .nav-toggle {
    display: none;
    background: none;
    border: none;
    padding: var(--space-sm);
    cursor: pointer;
    font-size: 1.25rem;
    color: var(--color-text);
  }
  
  @media (max-width: 768px) {
    .nav-toggle { display: block; }
    .main-nav ul {
      display: none;
      position: absolute;
      top: var(--header-height);
      left: 0;
      right: 0;
      background: var(--color-bg);
      border-bottom: 1px solid var(--color-border);
      flex-direction: column;
      padding: var(--space-md);
    }
    .main-nav ul.is-open { display: flex; }
  }
  
  /* ==========================================================================
     Buttons - use class .btn and .btn--primary / .btn--secondary
     ========================================================================== */
  .btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    border-radius: 6px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border-color 0.2s;
  }
  .btn:hover { text-decoration: none; }
  
  .btn--primary {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
  }
  .btn--primary:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    color: #fff;
  }
  
  .btn--secondary {
    background: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
  }
  .btn--secondary:hover {
    background: var(--color-primary);
    color: #fff;
  }
  
  .btn--accent {
    background: var(--color-accent);
    color: #fff;
    border-color: var(--color-accent);
  }
  .btn--accent:hover {
    background: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
    color: #fff;
  }
  
  /* ==========================================================================
     Sections - consistent vertical rhythm
     ========================================================================== */
  .section {
    padding-top: var(--space-xl);
    padding-bottom: var(--space-xl);
  }
  .section--alt { background-color: var(--color-bg-alt); }
  .section--dark {
    background-color: var(--color-primary-dark);
    color: #fff;
  }
  .section--dark a { color: #fff; opacity: 0.9; }
  .section--dark a:hover { opacity: 1; text-decoration: underline; }
  
  .section-title {
    margin-top: 0;
    margin-bottom: var(--space-sm);
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    color: var(--color-primary);
  }
  .section--dark .section-title { color: #fff; }
  .section-lead {
    margin-bottom: var(--space-lg);
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 60ch;
  }
  .section--dark .section-lead { color: rgba(255,255,255,0.85); }
  
  /* ==========================================================================
     Hero - home page hero block
     ========================================================================== */
  .hero {
    padding-top: var(--space-2xl);
    padding-bottom: var(--space-2xl);
    background: linear-gradient(135deg, var(--color-bg-alt) 0%, #e0e7ff 100%);
    text-align: center;
  }
  .hero-title {
    margin-top: 0;
    margin-bottom: var(--space-md);
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 800;
    color: var(--color-primary);
    line-height: 1.2;
  }
  .hero-lead {
    margin-bottom: var(--space-lg);
    font-size: 1.25rem;
    color: var(--color-text-muted);
    max-width: 55ch;
    margin-left: auto;
    margin-right: auto;
  }
  .hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-sm); justify-content: center; }
  
  /* ==========================================================================
     Service cards / grids - reusable for services and home
     ========================================================================== */
  .service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: var(--space-lg);
  }
  .service-card {
    padding: var(--space-lg);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: box-shadow 0.2s, border-color 0.2s;
  }
  .service-card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    border-color: var(--color-primary);
  }
  .service-card h3 {
    margin-top: 0;
    margin-bottom: var(--space-xs);
    font-size: 1.125rem;
    color: var(--color-primary);
  }
  .service-card p { margin: 0; font-size: 0.9375rem; color: var(--color-text-muted); }
  
  /* Subsections (e.g. B2C, B2B on services page) */
  .subsection {
    margin-bottom: var(--space-2xl);
  }
  .subsection:last-child { margin-bottom: 0; }
  .subsection-title {
    margin-top: 0;
    margin-bottom: var(--space-md);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    padding-bottom: var(--space-xs);
    border-bottom: 3px solid var(--color-accent);
  }
  
  /* Simple list of services (no cards) */
  .service-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--space-sm);
  }
  .service-list li {
    padding: var(--space-xs) 0;
    border-bottom: 1px solid var(--color-border);
  }
  .service-list li:last-child { border-bottom: none; }
  
  /* ==========================================================================
     Forms - contact and newsletter
     ========================================================================== */
  .form-group {
    margin-bottom: var(--space-md);
  }
  .form-group label {
    display: block;
    margin-bottom: var(--space-xs);
    font-weight: 600;
    color: var(--color-text);
  }
  .form-group input,
  .form-group select,
  .form-group textarea {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    font-family: inherit;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-bg);
  }
  .form-group input:focus,
  .form-group select:focus,
  .form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(13, 79, 139, 0.15);
  }
  .form-group textarea { min-height: 120px; resize: vertical; }
  
  .form-actions { margin-top: var(--space-lg); }
  .form-note { font-size: 0.875rem; color: var(--color-text-muted); margin-top: var(--space-sm); }
  
  /* Two-column form layout on larger screens */
  .form-grid {
    display: grid;
    gap: var(--space-lg);
  }
  @media (min-width: 600px) {
    .form-grid { grid-template-columns: 1fr 1fr; }
    .form-grid .form-group--full { grid-column: 1 / -1; }
  }
  
  /* ==========================================================================
     Footer
     ========================================================================== */
  .site-footer {
    padding-top: var(--space-xl);
    padding-bottom: var(--space-md);
    background: var(--color-primary-dark);
    color: #fff;
  }
  .site-footer a { color: rgba(255,255,255,0.9); }
  .site-footer a:hover { color: #fff; text-decoration: underline; }
  .footer-grid {
    display: grid;
    gap: var(--space-lg);
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    margin-bottom: var(--space-lg);
  }
  .footer-grid h4 {
    margin-top: 0;
    margin-bottom: var(--space-sm);
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #fff;
  }
  .footer-grid ul { margin: 0; padding: 0; list-style: none; }
  .footer-grid li { margin-bottom: var(--space-xs); }
  .footer-bottom {
    padding-top: var(--space-md);
    border-top: 1px solid rgba(255,255,255,0.2);
    font-size: 0.875rem;
    color: rgba(255,255,255,0.7);
    text-align: center;
  }
  
  /* ==========================================================================
     Utility
     ========================================================================== */
  .text-center { text-align: center; }
  .mt-0 { margin-top: 0; }
  .mb-0 { margin-bottom: 0; }