:root {
        --accent1:#651fff;
        --accent2:#7c4dff;
    }
    body {
        font-family: 'Poppins', sans-serif;
        margin: 0;
        background: #f9f9fb;
        color: #333;
        text-align: center;
        padding-bottom: 80px;
    }
    header {
        background: linear-gradient(90deg, var(--accent1), var(--accent2));
        color: white;
        padding: 16px 20px;
        font-size: 1.4em;
        font-weight: 600;
        display:flex;
        justify-content:space-between;
        align-items:center;
    }
    header a.home-link {
        color:#fff;
        text-decoration:none;
        font-size:.85rem;
        font-weight:600;
        opacity:.9;
        transition:opacity .3s ease;
    }
    header a.home-link:hover {
        opacity:1;
        text-decoration:underline;
    }
    h1 {
        margin: 48px 0 24px;
        color: var(--accent1);
        font-size:2.1rem;
    }
    .cta-group {
        margin-bottom:48px;
    }
    .btn {
        display: inline-block;
        padding: 14px 32px;
        margin: 10px;
        border-radius: 999px;
        text-decoration: none;
        color: white;
        font-weight: 600;
        font-size:1.05rem;
        transition: transform 0.25s ease, box-shadow 0.25s ease;
        background: linear-gradient(135deg, var(--accent1), var(--accent2));
        box-shadow:0 4px 12px rgba(0,0,0,.15);
    }
    .btn:hover {
        transform: translateY(-3px) scale(1.03);
        box-shadow:0 8px 20px rgba(0,0,0,.25), 0 0 12px var(--accent1), 0 0 24px var(--accent2);
    }
    section {
        max-width:800px;
        margin:0 auto 60px;
        padding:32px 24px;
        background:rgba(255,255,255,.75);
        backdrop-filter:blur(10px);
        -webkit-backdrop-filter:blur(10px);
        border-radius:16px;
        box-shadow:0 4px 20px rgba(0,0,0,.08);
        text-align:left;
    }
    section h2 {
        margin-top:0;
        color:var(--accent1);
    }
    .coming-soon {
        font-style:italic;
        color:#777;
        margin-top:12px;
    }
.mocktest-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(clamp(120px, 20vw, 150px), 1fr));
    gap: 8px;
    margin-top: 8px;
}

.studymaterial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(clamp(120px, 20vw, 150px), 1fr));
    gap: 8px;
    margin-top: 8px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.section-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 24px;
    max-width: 1000px;
    margin: 0 auto 60px;
    padding: 0 24px;
}

.section-row section {
    flex: 1 1 400px;
    max-width: 480px;
    background: rgba(255,255,255,.75);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,.08);
    padding: 32px 24px;
    text-align: left;
}

/* =============================================================
   ADD TO BOTTOM OF stylebm.css
   Dark mode support for Building Materials page
   ============================================================= */

/* Theme toggle button — sits inside nav ul in the header */
nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 16px;
}

nav ul li a {
  color: #fff;
  text-decoration: none;
}

.theme-toggle {
  background: transparent;
  border: 1.5px solid rgba(255,255,255,0.5);
  border-radius: 20px;
  cursor: pointer;
  font-size: 16px;
  padding: 4px 10px;
  line-height: 1;
  color: #fff;
  vertical-align: middle;
  transition: background 0.2s ease, border-color 0.2s ease;
}
.theme-toggle:hover {
  background: rgba(255,255,255,0.15);
  border-color: rgba(255,255,255,0.85);
}

/* Global transition */
*, *::before, *::after {
  transition: background-color 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

/* Dark mode overrides */
[data-theme="dark"] body {
  background-color: #121212;
  color: #e0e0e0;
}

[data-theme="dark"] h1,
[data-theme="dark"] h2,
[data-theme="dark"] h3 {
  color: #90caf9;
}

[data-theme="dark"] p {
  color: #cccccc;
}

[data-theme="dark"] .section-row section {
  background-color: #1e1e1e;
  border-color: #333;
}

[data-theme="dark"] .btn {
  background: linear-gradient(135deg, var(--accent1), var(--accent2));
  color: #fff !important;
  border: none;
  text-shadow: 0 1px 3px rgba(0,0,0,0.4);
}
[data-theme="dark"] .btn:hover {
  background: linear-gradient(135deg, var(--accent1), var(--accent2));
  color: #fff !important;
  box-shadow: 0 8px 20px rgba(0,0,0,.35), 0 0 14px var(--accent1), 0 0 28px var(--accent2);
}

[data-theme="dark"] footer.footer {
  background-color: #1a1a1a;
  color: #aaaaaa;
}