.as-scitech {
      --as-bg: #fafaf7;
      --as-surface: #ffffff;
      --as-surface-alt: #f3f5f8;
      --as-border: #d9e0e8;
      --as-border-strong: #b8c4d0;
      --as-text: #18222d;
      --as-text-muted: #4b5a6a;
      --as-primary: #0f4c81;
      --as-primary-soft: #e7f0f8;
      --as-accent: #b45309;
      --as-accent-soft: #fef3c7;
      --as-success: #15803d;
      --as-success-soft: #dcfce7;
      --as-danger: #b91c1c;
      --as-danger-soft: #fee2e2;
      --as-Neutral-badge: #334155;
      --as-shadow: 0 2px 10px rgba(15, 34, 58, 0.06);
      --as-radius: 10px;
      font-family: 'Noto Sans Devanagari', 'Hind', 'Kohinoor Devanagari', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      color: var(--as-text);
      background-color: var(--as-bg);
      line-height: 1.78;
      font-size: 16.5px;
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    .as-scitech *, .as-scitech *::before, .as-scitech *::after {
      box-sizing: border-box;
    }

    .as-scitech .as-container {
      max-width: 1320px;
      margin: 0 auto;
      padding: 1.5rem 1.25rem 3.5rem;
    }

    /* Breadcrumb */
    .as-scitech .as-breadcrumb {
      font-size: 0.88rem;
      color: var(--as-text-muted);
      margin-bottom: 1rem;
      display: flex;
      flex-wrap: wrap;
      gap: 0.4rem;
      align-items: center;
    }
    .as-scitech .as-breadcrumb a {
      color: var(--as-primary);
      text-decoration: none;
      font-weight: 500;
    }
    .as-scitech .as-breadcrumb a:hover {
      text-decoration: underline;
    }

    /* Chapter Hero Header */
    .as-scitech .as-hero {
      background: linear-gradient(135deg, #0b3559 0%, #134e7e 60%, #1b639b 100%);
      color: #ffffff;
      border-radius: 14px;
      padding: 2rem 2.2rem;
      margin-bottom: 1.75rem;
      box-shadow: 0 8px 24px rgba(11, 53, 89, 0.14);
    }

    .as-scitech .as-hero-badges {
      display: flex;
      flex-wrap: wrap;
      gap: 0.55rem;
      margin-bottom: 0.85rem;
    }

    .as-scitech .as-badge {
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.28);
      color: #f8fafc;
      font-size: 0.8rem;
      font-weight: 600;
      padding: 0.25rem 0.7rem;
      border-radius: 999px;
      letter-spacing: 0.02em;
    }

    .as-scitech .as-badge-gold {
      background: #f59e0b;
      border-color: #fbbf24;
      color: #111827;
    }

    .as-scitech .as-h1 {
      font-size: clamp(1.6rem, 2.8vw, 2.35rem);
      line-height: 1.32;
      margin: 0 0 0.55rem 0;
      font-weight: 800;
      color: #ffffff;
    }

    .as-scitech .as-subtitle {
      font-size: 1.05rem;
      color: #dbeafe;
      margin: 0 0 1.2rem 0;
      font-weight: 400;
    }

    .as-scitech .as-syllabus-bar {
      background: rgba(255, 255, 255, 0.1);
      border-left: 4px solid #fbbf24;
      padding: 0.85rem 1.1rem;
      border-radius: 6px;
      font-size: 0.93rem;
      color: #f1f5f9;
    }

    /* Two-column layout: Wide Main Article + Sticky Right Important Facts */
    .as-scitech .as-layout {
      display: grid;
      grid-template-columns: minmax(0, 1fr) 340px;
      gap: 1.85rem;
      align-items: start;
    }

    @media (max-width: 1024px) {
      .as-scitech .as-layout {
        grid-template-columns: 1fr;
      }
    }

    .as-scitech .as-main {
      min-width: 0;
    }

    /* Sticky Right Sidebar */
    .as-scitech .as-sidebar {
      position: sticky;
      top: 1.25rem;
      background: var(--as-surface);
      border: 1px solid var(--as-border);
      border-top: 4px solid var(--as-primary);
      border-radius: var(--as-radius);
      padding: 1.25rem 1.2rem;
      box-shadow: var(--as-shadow);
      max-height: calc(100vh - 2.5rem);
      overflow-y: auto;
    }

    @media (max-width: 1024px) {
      .as-scitech .as-sidebar {
        position: static;
        max-height: none;
        margin-top: 1.5rem;
      }
    }

    .as-scitech .as-sidebar-title {
      font-size: 1.08rem;
      font-weight: 700;
      color: var(--as-primary);
      margin: 0 0 0.85rem 0;
      padding-bottom: 0.55rem;
      border-bottom: 2px solid var(--as-primary-soft);
      display: flex;
      align-items: center;
      gap: 0.45rem;
    }

    .as-scitech .as-fact-list {
      list-style: none;
      margin: 0;
      padding: 0;
      display: flex;
      flex-direction: column;
      gap: 0.7rem;
    }

    .as-scitech .as-fact-item {
      background: var(--as-surface-alt);
      border-left: 3px solid var(--as-primary);
      padding: 0.6rem 0.75rem;
      border-radius: 0 6px 6px 0;
      font-size: 0.89rem;
      line-height: 1.52;
    }

    .as-scitech .as-fact-item strong {
      color: #0b3559;
      display: block;
      margin-bottom: 0.15rem;
    }

    /* Content Sections */
    .as-scitech .as-section {
      background: var(--as-surface);
      border: 1px solid var(--as-border);
      border-radius: var(--as-radius);
      padding: 1.75rem 1.9rem;
      margin-bottom: 1.6rem;
      box-shadow: var(--as-shadow);
    }

    @media (max-width: 640px) {
      .as-scitech .as-section {
        padding: 1.25rem 1.1rem;
      }
      .as-scitech .as-hero {
        padding: 1.4rem 1.2rem;
      }
    }

    .as-scitech .as-section-header {
      display: flex;
      align-items: baseline;
      gap: 0.75rem;
      border-bottom: 2px solid var(--as-primary-soft);
      padding-bottom: 0.65rem;
      margin-bottom: 1.25rem;
    }

    .as-scitech .as-sec-num {
      background: var(--as-primary);
      color: #ffffff;
      font-weight: 700;
      font-size: 0.85rem;
      padding: 0.2rem 0.6rem;
      border-radius: 6px;
      flex-shrink: 0;
    }

    .as-scitech .as-h2 {
      font-size: 1.42rem;
      font-weight: 800;
      color: #0b3559;
      margin: 0;
      line-height: 1.35;
    }

    .as-scitech .as-h3 {
      font-size: 1.16rem;
      font-weight: 700;
      color: #134e7e;
      margin: 1.5rem 0 0.65rem 0;
      line-height: 1.4;
    }

    .as-scitech .as-h4 {
      font-size: 1.02rem;
      font-weight: 700;
      color: #1e293b;
      margin: 1.1rem 0 0.45rem 0;
    }

    .as-scitech p {
      margin: 0 0 1rem 0;
      text-align: left;
    }

    .as-scitech ul, .as-scitech ol {
      margin: 0 0 1.1rem 0;
      padding-left: 1.4rem;
    }

    .as-scitech li {
      margin-bottom: 0.45rem;
    }

    /* Callout & Info Boxes */
    .as-scitech .as-callout {
      background: var(--as-primary-soft);
      border-left: 4px solid var(--as-primary);
      padding: 1.05rem 1.25rem;
      border-radius: 0 8px 8px 0;
      margin: 1.1rem 0;
    }

    .as-scitech .as-callout-warn {
      background: var(--as-accent-soft);
      border-left: 4px solid var(--as-accent);
    }

    .as-scitech .as-callout-title {
      font-weight: 700;
      color: #0b3559;
      margin-bottom: 0.4rem;
      display: block;
    }

    .as-scitech .as-callout-warn .as-callout-title {
      color: #92400e;
    }

    /* Responsive Tables */
    .as-scitech .as-table-wrap {
      width: 100%;
      overflow-x: auto;
      margin: 1.15rem 0 1.35rem;
      border: 1px solid var(--as-border);
      border-radius: 8px;
    }

    .as-scitech table {
      width: 100%;
      border-collapse: collapse;
      font-size: 0.94rem;
      min-width: 560px;
    }

    .as-scitech th {
      background: #0f4c81;
      color: #ffffff;
      font-weight: 700;
      text-align: left;
      padding: 0.75rem 0.9rem;
      border-bottom: 2px solid #0b3559;
    }

    .as-scitech td {
      padding: 0.7rem 0.9rem;
      border-bottom: 1px solid var(--as-border);
      vertical-align: top;
    }

    .as-scitech tr:nth-child(even) td {
      background-color: #f8fafc;
    }

    /* Flow Diagram */
    .as-scitech .as-flow {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(175px, 1fr));
      gap: 0.75rem;
      margin: 1.2rem 0;
    }

    .as-scitech .as-flow-step {
      background: var(--as-surface-alt);
      border: 1px solid var(--as-border-strong);
      border-top: 3px solid var(--as-primary);
      border-radius: 8px;
      padding: 0.85rem;
      font-size: 0.91rem;
    }

    .as-scitech .as-flow-step-num {
      font-size: 0.78rem;
      font-weight: 700;
      color: var(--as-primary);
      text-transform: uppercase;
      display: block;
      margin-bottom: 0.25rem;
    }

    /* Grid Cards for comparisons */
    .as-scitech .as-grid-2 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 1.1rem;
      margin: 1rem 0;
    }

    .as-scitech .as-card {
      background: var(--as-surface-alt);
      border: 1px solid var(--as-border);
      border-radius: 8px;
      padding: 1.1rem 1.2rem;
    }

    /* Interactive MCQ Cards */
    .as-scitech .as-mcq-card {
      border: 1px solid var(--as-border-strong);
      border-radius: 10px;
      padding: 1.3rem 1.4rem;
      margin-bottom: 1.35rem;
      background: #ffffff;
    }

    .as-scitech .as-mcq-meta {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      gap: 0.5rem;
      margin-bottom: 0.75rem;
      font-size: 0.83rem;
    }

    .as-scitech .as-mcq-tag {
      background: #e0f2fe;
      color: #0369a1;
      font-weight: 700;
      padding: 0.2rem 0.65rem;
      border-radius: 999px;
    }

    .as-scitech .as-mcq-tag-pyq {
      background: #fef3c7;
      color: #92400e;
      border: 1px solid #f59e0b;
    }

    .as-scitech .as-mcq-status {
      color: var(--as-text-muted);
      font-weight: 600;
    }

    .as-scitech .as-mcq-q {
      font-weight: 700;
      font-size: 1.03rem;
      color: #0f172a;
      margin-bottom: 0.9rem;
      white-space: pre-line;
    }

    .as-scitech .as-mcq-options {
      display: flex;
      flex-direction: column;
      gap: 0.55rem;
      margin-bottom: 0.85rem;
    }

    .as-scitech .as-mcq-opt {
      display: flex;
      align-items: flex-start;
      gap: 0.65rem;
      width: 100%;
      text-align: left;
      background: #f8fafc;
      border: 1.5px solid var(--as-border-strong);
      border-radius: 8px;
      padding: 0.7rem 0.95rem;
      font-family: inherit;
      font-size: 0.96rem;
      color: var(--as-text);
      cursor: pointer;
      transition: background-color 0.15s ease, border-color 0.15s ease;
    }

    .as-scitech .as-mcq-opt:hover:not(:disabled) {
      background: #eff6ff;
      border-color: var(--as-primary);
    }

    .as-scitech .as-mcq-opt:focus-visible {
      outline: 3px solid #2563eb;
      outline-offset: 2px;
    }

    .as-scitech .as-mcq-opt.as-opt-correct {
      background: var(--as-success-soft);
      border-color: var(--as-success);
      color: #064e3b;
      font-weight: 700;
    }

    .as-scitech .as-mcq-opt.as-opt-wrong {
      background: var(--as-danger-soft);
      border-color: var(--as-danger);
      color: #7f1d1d;
    }

    .as-scitech .as-mcq-feedback {
      margin-top: 0.75rem;
      padding: 0.95rem 1.1rem;
      border-radius: 8px;
      background: #f1f5f9;
      border-left: 4px solid var(--as-primary);
      font-size: 0.93rem;
      display: none;
    }

    .as-scitech .as-mcq-feedback.as-visible {
      display: block;
    }

    .as-scitech .as-mcq-actions {
      display: flex;
      gap: 0.75rem;
      margin-top: 0.6rem;
      align-items: center;
    }

    .as-scitech .as-btn-reset {
      background: transparent;
      border: 1px solid var(--as-border-strong);
      color: var(--as-text-muted);
      padding: 0.35rem 0.75rem;
      border-radius: 6px;
      font-family: inherit;
      font-size: 0.82rem;
      cursor: pointer;
    }

    .as-scitech .as-btn-reset:hover {
      background: var(--as-surface-alt);
      color: var(--as-text);
    }

    /* Progressive enhancement fallback details */
    .as-scitech details.as-noscript-exp {
      margin-top: 0.5rem;
      font-size: 0.91rem;
      color: var(--as-text-muted);
    }
    .as-scitech details.as-noscript-exp summary {
      cursor: pointer;
      font-weight: 600;
      color: var(--as-primary);
    }

    /* Mains Model Answer Card */
    .as-scitech .as-mains-card {
      border: 1px solid var(--as-border-strong);
      border-top: 4px solid #0f4c81;
      border-radius: 10px;
      padding: 1.4rem 1.5rem;
      margin-bottom: 1.5rem;
      background: #ffffff;
    }

    .as-scitech .as-mains-q {
      font-size: 1.07rem;
      font-weight: 700;
      color: #0b3559;
      margin-bottom: 0.85rem;
      padding-bottom: 0.65rem;
      border-bottom: 1px dashed var(--as-border-strong);
    }

    /* Sources links */
    .as-scitech .as-source-list a {
      color: var(--as-primary);
      word-break: break-word;
    }
  
.as-scitech{--as-bg:var(--ds-bg,#f8fafc);--as-surface:var(--ds-surface,#fff);--as-surface-alt:var(--ds-surface-soft,#f1f5f9);--as-border:var(--ds-border,#dfe4e8);--as-border-strong:var(--ds-border-strong,#b8c4d0);--as-text:var(--ds-text,#1e293b);--as-text-muted:var(--ds-text-muted,#475569);--as-primary:var(--ds-primary,#2457a6);--as-primary-soft:var(--ds-primary-soft,#eef4ff);--as-success:var(--ds-success,#146c52);--as-success-soft:var(--ds-success-soft,#edf7f0);--as-danger:var(--ds-danger,#b2343c);--as-danger-soft:var(--ds-danger-soft,#fdf0f1);--as-shadow:none;background:transparent;font-family:var(--ds-font-body,'Noto Sans Devanagari',sans-serif);font-size:1.04rem}
.as-scitech .as-container{max-width:1160px;padding:23px 16px 55px}.as-scitech .as-layout{grid-template-columns:minmax(0,1fr) 292px;gap:22px}
.as-scitech .as-hero{background:var(--ds-surface);color:var(--ds-text);border:1px solid var(--ds-border);border-radius:14px;box-shadow:none;padding:27px 30px}
.as-scitech .as-h1,.as-scitech .as-h2{color:var(--ds-heading,#0f172a)}.as-scitech .as-subtitle{color:var(--ds-text-muted)}
.as-scitech .as-badge{background:var(--ds-primary-soft);color:var(--ds-primary);border-color:var(--ds-border)}.as-scitech .as-badge-gold{background:var(--ds-accent-soft);color:var(--ds-accent)}
.as-scitech .as-syllabus-bar{background:var(--ds-surface-soft);color:var(--ds-text);border-left-color:var(--ds-primary)}
.as-scitech .as-section{box-shadow:none;border-color:var(--ds-border);border-radius:12px}.as-scitech .as-h3,.as-scitech .as-sidebar-title{color:var(--ds-primary)}
.as-scitech .as-sidebar{top:85px;max-height:none;overflow:visible;box-shadow:none;border-color:var(--ds-border)}
.as-scitech .as-fact-item{background:var(--ds-surface-soft)}.as-scitech .as-fact-item strong{color:var(--ds-primary)}
.as-scitech .as-table-wrap{max-width:100%}.as-scitech th{background:var(--ds-primary-strong,#17427f);color:#fff}.as-scitech td{color:var(--ds-text)}
.as-scitech tr:nth-child(even) td{background:var(--ds-surface-soft)}
.as-scitech .as-mcq-card,.as-scitech .as-mains-card{background:var(--ds-surface);border-color:var(--ds-border-strong)}
.as-scitech .as-mcq-q,.as-scitech .as-mains-q{color:var(--ds-heading)}
.as-scitech .as-mcq-opt{background:var(--ds-surface-soft);color:var(--ds-text);border-color:var(--ds-border)}
.as-scitech .as-mcq-opt.as-opt-correct{background:var(--ds-success-soft);border-color:var(--ds-success);color:var(--ds-success)}.as-scitech .as-mcq-opt.as-opt-wrong{background:var(--ds-danger-soft);border-color:var(--ds-danger);color:var(--ds-danger)}
.as-scitech .as-mcq-feedback{background:var(--ds-surface-soft);color:var(--ds-text)}
.as-scitech .as-choice-result{display:block;font-weight:800;color:var(--ds-danger);margin-bottom:7px}.as-scitech .as-choice-result.is-correct{color:var(--ds-success)}
.as-scitech .as-mcq-tag-pyq{color:var(--ds-accent,#8a5a12);background:var(--ds-accent-soft,#fff4d6)}
.as-scitech .as-section p,.as-scitech .as-section li{overflow-wrap:anywhere}
.science-chapter-bottom{max-width:1160px;margin:auto;padding:0 16px 60px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:15px}
.science-chapter-bottom a{color:var(--ds-primary);font-weight:750;text-decoration:none}
@media(max-width:1024px){.as-scitech .as-layout{grid-template-columns:minmax(0,1fr)}.as-scitech .as-sidebar{position:static}}
@media(max-width:650px){.as-scitech .as-container{padding:16px 12px 45px}.as-scitech .as-hero{padding:21px 17px}.as-scitech .as-section{padding:19px 15px}.as-scitech .as-mcq-card,.as-scitech .as-mains-card{padding:17px 14px}.science-chapter-bottom{padding:0 12px 40px}}

/* SCIENCE_READER_TWO_COLUMN_V2: expand the chapter, preserve the important-facts rail. */
.as-scitech .as-container {
  width: 100%;
  max-width: 1600px;
}
body[data-as-layout="study"] .as-scitech .as-layout > .as-main.as-reading-content {
  width: 100%;
  max-width: none;
  min-width: 0;
  margin-inline: 0;
  padding-inline: 0;
}
@media (min-width: 1025px) {
  .as-scitech .as-container {
    padding-inline: clamp(16px, 2vw, 32px);
  }
  .as-scitech .as-layout {
    grid-template-columns: minmax(0, 1fr) 292px;
    gap: clamp(18px, 2vw, 30px);
    align-items: start;
  }
}

/* Science chapters: matching text contrast across light and dark reading modes.
   Use the site's design tokens; keep question feedback and paragraph highlight legible. */
.as-scitech{
  --as-accent:var(--ds-accent,#8a5a12);
  --as-accent-soft:var(--ds-accent-soft,#fff4d6);
}
.as-scitech .as-h4,
.as-scitech .as-callout-title{color:var(--ds-heading,#0f172a)}
.as-scitech .as-callout-warn .as-callout-title{color:var(--ds-accent,#8a5a12)}
.as-scitech .as-mcq-tag{color:var(--ds-primary,#2457a6);background:var(--ds-primary-soft,#eef4ff)}
.as-scitech .as-mcq-tag-pyq{color:var(--ds-accent,#8a5a12);background:var(--ds-accent-soft,#fff4d6);border-color:var(--ds-accent,#8a5a12)}
.as-scitech .as-sec-num,
.as-scitech th{color:var(--ds-on-primary,#fff)}
.as-scitech .as-mcq-opt:hover:not(:disabled){background:var(--ds-primary-soft,#eef4ff);color:var(--ds-text,#1e293b);border-color:var(--ds-primary,#2457a6)}
.as-scitech .as-mcq-opt.as-opt-correct:hover:not(:disabled){background:var(--ds-success-soft,#edf7f0);color:var(--ds-success,#146c52);border-color:var(--ds-success,#146c52)}
.as-scitech .as-mcq-opt.as-opt-wrong:hover:not(:disabled){background:var(--ds-danger-soft,#fdf0f1);color:var(--ds-danger,#b2343c);border-color:var(--ds-danger,#b2343c)}
html[data-theme="dark"] .as-scitech [style*="background:#f1f5f9"],
html[data-theme="dark"] .as-scitech [style*="background: #f1f5f9"],
html[data-theme="dark"] .as-scitech [style*="background:#e7f0f8"],
html[data-theme="dark"] .as-scitech [style*="background: #e7f0f8"]{
  background:var(--ds-surface-soft,#1e293b)!important;
  color:var(--ds-text,#e2e8f0)!important;
}
.as-scitech :is(.as-card,.as-flow-step,.as-callout,.as-mcq-feedback){color:var(--ds-text,#1e293b)}
.as-scitech :is(.as-sidebar,.as-section,.as-mcq-card,.as-mains-card){color:var(--ds-text,#1e293b)}
@media(max-width:640px){
  .as-scitech .as-section-header{flex-wrap:wrap}
  .as-scitech .as-grid-2{grid-template-columns:minmax(0,1fr)}
}

/* Chapter diagrams & formula fallback: shared styles instead of per-page CSS. */
.as-scitech .as-svg-box{
  background:var(--ds-surface-soft,#f1f5f9);
  border:1px solid var(--ds-border,#dedede);
  border-radius:10px;
  padding:1rem;
  margin:1.25rem 0;
  text-align:center;
  max-width:100%;
  overflow-x:auto;
}
.as-scitech .as-svg-cap{
  font-size:.87rem;
  color:var(--ds-text-muted,#475569);
  margin-top:.55rem;
  font-weight:600;
}
.as-scitech .as-math-fallback{
  font-family:var(--ds-font-body,'Noto Sans Devanagari',system-ui,sans-serif);
  color:var(--ds-text,#1e293b);
  font-variant-numeric:lining-nums;
  overflow-wrap:anywhere;
  unicode-bidi:isolate;
}
.as-scitech .as-math-fallback-block{
  margin:1rem 0;
  padding:.65rem .75rem;
  background:var(--ds-surface-soft,#f1f5f9);
  border:1px solid var(--ds-border,#dedede);
  border-radius:8px;
  overflow-x:auto;
  text-align:center;
  font-size:1.06em;
}
.as-scitech .as-svg-box svg{max-width:100%;height:auto}

/* All science chapters: align source quiz event classes with accessible shared feedback states. */
.as-scitech .as-mcq-opt.is-correct,.as-scitech .as-mcq-opt.is-correct:hover{background:var(--ds-success-soft,#edf7f0);border-color:var(--ds-success,#146c52);color:var(--ds-success,#146c52);font-weight:750}
.as-scitech .as-mcq-opt.is-wrong,.as-scitech .as-mcq-opt.is-wrong:hover{background:var(--ds-danger-soft,#fdf0f1);border-color:var(--ds-danger,#b2343c);color:var(--ds-danger,#b2343c)}
.as-scitech .as-mcq-feedback.is-visible{display:block}
.as-scitech .as-mcq-opt:disabled{cursor:default;opacity:1}