@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* =========================================================
       PHASE 1 — DESIGN SYSTEM & CORE STYLES
       ========================================================= */
    :root {
  --shadow-sm   : 0 2px 8px rgba(0,0,0,0.06);
  --shadow-md   : 0 4px 20px rgba(0,0,0,0.10);
  --shadow-lg   : 0 8px 32px rgba(0,0,0,0.14);
  --radius-sm   : 8px;
  --radius-md   : 12px;
  --radius-lg   : 18px;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --dur-fast: 150ms;
  --dur-base: 250ms;
  --dur-slow: 400ms;
  --dur-tap: 80ms;

  --transition-fast : all var(--dur-fast) var(--ease-out);
  --transition-base : all var(--dur-base) var(--ease-out);

      --primary: #111111;
      --secondary: #ff6f00;
      --surface: #ffffff;
      --background: #f0f4ff;
      --text-primary: #1a1a2e;
      --text-muted: #6b7280;
      --success: #10b981;
      --danger: #ef4444;
      --radius: 12px;
      --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
      --transition: all var(--dur-base) var(--ease-out);
      --container: 1120px;
      --header-height: 72px;
    }

    *, *::before, *::after { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      font-family: "Inter", "Segoe UI", Roboto, Arial, sans-serif;
      color: var(--text-primary);
      background: var(--background);
      font-size: 16px;
      line-height: 1.7;
      overflow-x: hidden;
    }
    p { line-height: 1.7; }
    h1, h2, h3, h4, h5, h6 { line-height: 1.25; }
    img, svg, canvas { display: block; max-width: 100%; }
    a { color: inherit; text-decoration: none; }
    .container { width: min(100% - 2rem, var(--container)); margin-inline: auto; }
    .section { padding: 5rem 0; }

    /* Scroll reveal */
    .reveal {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity var(--dur-slow) var(--ease-out),
                  transform var(--dur-slow) var(--ease-out);
    }
    .reveal.is-visible {
      opacity: 1;
      transform: none;
    }
    @media (prefers-reduced-motion: reduce) {
      .reveal { opacity: 1; transform: none; }
    }

    /* =========================================================
       Utility Components
       ========================================================= */
    .card {
      background: var(--surface);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-md);
      border: 1px solid rgba(17,17,17,0.10);
      transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out);
      will-change: transform;
      position: relative;
    }
    @media (hover: hover) and (pointer: fine) {
      .card:hover {
        transform: translateY(-3px);
        box-shadow: 0 8px 24px rgba(0,0,0,0.08);
      }
    }
    .card:focus-within {
      box-shadow: var(--shadow-lg);
      border-color: rgba(17,17,17,0.18);
    }

    .stat-card, .member-card, .formula-card, .apd-card {
      transition: var(--transition-base);
      will-change: transform;
    }
    @media (hover: hover) and (pointer: fine) {
      .stat-card:hover, .member-card:hover, .formula-card:hover, .apd-card:hover {
        transform: translateY(-4px);
        box-shadow: var(--shadow-lg);
      }
    }

    .btn-primary, .btn-secondary {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      min-height: 46px;
      padding: 0.75rem 1.25rem;
      border-radius: var(--radius-sm);
      font-weight: 600;
      border: 2px solid transparent;
      cursor: pointer;
      transition: transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), background-color var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
      user-select: none;
      white-space: nowrap;
    }
    .btn-primary {
      color: #fff;
      background: linear-gradient(135deg, var(--primary), #2b2b2b);
      box-shadow: 0 8px 20px rgba(17,17,17,0.28), inset 0 1px 0 rgba(255,255,255,0.15);
      will-change: transform;
      overflow: hidden;
      position: relative;
      transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out);
    }
    @media (hover: hover) and (pointer: fine) {
      .btn-primary:hover {
        transform: translateY(-2px);
        box-shadow: 0 10px 26px rgba(17,17,17,0.24), inset 0 1px 0 rgba(255,255,255,0.18);
        outline: none;
      }
    }
    .btn-primary:focus-visible {
      transform: translateY(-2px);
      box-shadow: 0 10px 26px rgba(17,17,17,0.24), inset 0 1px 0 rgba(255,255,255,0.18);
      outline: none;
    }
    .btn-secondary { color: var(--primary); background: transparent; border-color: rgba(17,17,17,0.35); }
    @media (hover: hover) and (pointer: fine) {
      .btn-secondary:hover {
        color: var(--primary);
        background: rgba(17,17,17,0.10);
        border-color: rgba(17,17,17,0.45);
        outline: none;
      }
    }
    .btn-secondary:focus-visible {
      color: var(--primary);
      background: rgba(17,17,17,0.10);
      border-color: rgba(17,17,17,0.45);
      outline: none;
    }
    .btn-primary:active  { transform: translateY(0) scale(0.98); transition-duration: var(--dur-tap); }
    .btn-secondary:active { transform: scale(0.97); }

    /* Ripple */
    .ripple {
      position: absolute;
      border-radius: 50%;
      width: 80px;
      height: 80px;
      background: rgba(255,255,255,0.25);
      transform: scale(0);
      animation: rippleAnim var(--dur-slow) var(--ease-out) forwards;
      pointer-events: none;
      margin: -40px 0 0 -40px;
    }
    @keyframes rippleAnim {
      to { transform: scale(3); opacity: 0; }
    }

    .btn-primary:focus-visible,
    .btn-secondary:focus-visible,
    a:focus-visible,
    button:focus-visible,
    input:focus-visible,
    select:focus-visible,
    textarea:focus-visible {
      outline: 2px solid var(--primary);
      outline-offset: 3px;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      gap: 0.4rem;
      width: fit-content;
      padding: 0.35rem 0.75rem;
      border-radius: 999px;
      font-size: 0.82rem;
      font-weight: 800;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      color: #ffffff;
      background: linear-gradient(120deg, var(--primary), var(--secondary));
      border: 1px solid rgba(255, 255, 255, 0.18);
      box-shadow: var(--shadow-sm);
    }
    .section-title { margin: 0 0 0.6rem; font-size: clamp(1.4rem, 2.5vw, 2.1rem); line-height: 1.25; color: var(--primary); letter-spacing: 0.01em; }
    .section-subtitle { margin: 0; color: var(--text-muted); font-size: 1rem; }

    .grid-2, .grid-3 { display: grid; gap: 1rem; }
    .grid-2 { grid-template-columns: repeat(2, minmax(0,1fr)); }
    .grid-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
    @media (max-width: 900px) { .grid-3 { grid-template-columns: repeat(2, minmax(0,1fr)); } }
    @media (max-width: 700px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

    /* =========================================================
       Scroll Progress
       ========================================================= */
    .scroll-progress { position: fixed; top: 0; left: 0; width: 100%; height: 4px; z-index: 1100; background: rgba(255,255,255,0.35); backdrop-filter: blur(2px); }
    .scroll-progress__bar { height: 100%; width: 0; background: linear-gradient(90deg,var(--secondary),#ff9d3f); transition: width 0.1s linear; }

    /* =========================================================
       Loading Screen
       ========================================================= */
    .loader-screen { position: fixed; inset: 0; z-index: 1200; display: grid; place-items: center; background: var(--primary); color: #fff; transition: opacity 0.7s ease, visibility 0.7s ease; }
    .loader-screen.is-hidden { opacity: 0; visibility: hidden; pointer-events: none; }
    .loader-content { text-align: center; padding: 1rem; }
    .loader-brand { margin: 0 0 0.75rem; font-size: clamp(1.2rem,3vw,2rem); font-weight: 800; letter-spacing: 0.02em; opacity: 0; animation: fadeInBrand 1.1s ease forwards; }
    .loader-text { margin: 0.65rem 0 0; font-size: 0.95rem; opacity: 0.9; }
    .loader-wave { width: min(320px,85vw); height: 80px; margin-inline: auto; }
    .loader-wave path { stroke: #fff; stroke-width: 4; fill: none; stroke-linecap: round; stroke-dasharray: 220; stroke-dashoffset: 220; animation: drawWave 1.4s ease-in-out infinite; }
    @keyframes drawWave { 0% { stroke-dashoffset: 220; } 50% { stroke-dashoffset: 0; } 100% { stroke-dashoffset: -220; } }
    @keyframes fadeInBrand { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

    /* =========================================================
       Navigation
       ========================================================= */
    .site-header { position: sticky; top: 0; z-index: 1000; backdrop-filter: blur(16px) saturate(180%); -webkit-backdrop-filter: blur(16px) saturate(180%); background: rgba(240,244,255,0.88); border-bottom: 1px solid transparent; }
    .site-header::after {
      content: "";
      position: absolute;
      left: 0;
      right: 0;
      bottom: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(79, 99, 210, 0.35), rgba(255, 157, 63, 0.25), transparent);
      pointer-events: none;
    }
    .navbar { min-height: var(--header-height); display: flex; align-items: center; justify-content: space-between; gap: 1rem; transition: box-shadow var(--dur-base) var(--ease-out), background var(--dur-base) var(--ease-out); }
    .navbar.scrolled { box-shadow: 0 2px 16px rgba(0,0,0,0.08); background: rgba(255,255,255,0.95); backdrop-filter: blur(8px); }
    .brand { display: inline-flex; align-items: center; gap: 0.55rem; font-weight: 800; color: var(--primary); font-size: 1rem; letter-spacing: 0.01em; }
    .brand svg { width: 24px; height: 24px; color: var(--secondary); }
    .menu-toggle { display: none; }
    .menu-button { display: none; width: 44px; height: 44px; border-radius: 10px; border: 1px solid rgba(17,17,17,0.2); background: #fff; align-items: center; justify-content: center; cursor: pointer; transition: var(--transition); }
    .menu-button span, .menu-button span::before, .menu-button span::after { display: block; width: 18px; height: 2px; border-radius: 2px; background: var(--primary); position: relative; transition: var(--transition); content: ""; }
    .menu-button span::before { top: -6px; position: absolute; left: 0; }
    .menu-button span::after { top: 6px; position: absolute; left: 0; }
    .nav-links { display: flex; align-items: center; gap: 0.5rem; list-style: none; margin: 0; padding: 0; }
    .nav-links a { position: relative; display: inline-flex; padding: 0.5rem 0.85rem; border-radius: 8px; font-size: 0.95rem; color: var(--text-primary); transition: var(--transition-fast); }
    .nav-links a:hover { color: var(--primary); background: rgba(17,17,17,0.07); }
    .nav-links a.is-active { color: var(--primary); font-weight: 700; background: rgba(17,17,17,0.12); }

    .nav-links a { position: relative; }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: #111111;
      transition: width var(--dur-base) var(--ease-out);
    }
    .nav-links a:hover::after,
    .nav-links a:focus-visible::after,
    .nav-links a.active::after,
    .nav-links a.is-active::after {
      width: 100%;
    }

    .nav-links a.is-active::before {
      content: "";
      position: absolute;
      left: 0.35rem;
      top: 50%;
      transform: translateY(-50%);
      width: 3px;
      height: 60%;
      border-radius: 3px;
      background: var(--secondary);
    }
    @media (max-width: 860px) {
      .menu-button { display: inline-flex; }
      .nav-wrap { position: absolute; top: calc(var(--header-height) + 1px); right: 1rem; left: 1rem; background: #fff; border: 1px solid rgba(17,17,17,0.12); border-radius: var(--radius); box-shadow: var(--shadow); max-height: 0; overflow: hidden; opacity: 0; visibility: hidden; transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.25s ease, visibility 0.25s ease; }
      .nav-links { flex-direction: column; align-items: stretch; padding: 0.6rem; }
      .nav-links a { padding: 0.7rem 0.85rem; }
      .menu-toggle:checked ~ .nav-wrap { max-height: 70vh; opacity: 1; visibility: visible; }
      .menu-toggle:checked + .menu-button span { background: transparent; }
      .menu-toggle:checked + .menu-button span::before { transform: translateY(6px) rotate(45deg); }
      .menu-toggle:checked + .menu-button span::after { transform: translateY(-6px) rotate(-45deg); }
    }

    /* =========================================================
       Hero
       ========================================================= */
    .hero { position: relative; min-height: calc(100vh - var(--header-height)); display: flex; align-items: center; padding: 6rem 0 3rem; overflow: hidden; overflow: clip; background: #ffffff; }
    .hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background:
        radial-gradient(80% 60% at 20% 10%, rgba(17,17,17,0.10), transparent 60%),
        radial-gradient(60% 55% at 85% 30%, rgba(255, 157, 63, 0.10), transparent 62%);
      background-size: 130% 130%, 140% 140%;
      background-position: 0% 0%, 100% 0%;
      pointer-events: none;
      z-index: 0;
    }

    .hero-watermark { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: min(75vw, 560px); height: auto; opacity: 0.22; pointer-events: none; user-select: none; z-index: 1; object-fit: contain; }
    #heroCanvas { position: absolute; inset: 0; z-index: 2; }
    .hero .container { position: relative; z-index: 3; }
    .hero-content { max-width: 760px; }
    .hero-title { margin: 0.7rem 0 0.75rem; font-size: clamp(2.4rem, 5vw, 3.8rem); line-height: 1.25; color: #111111; min-height: 1.2em; }
    .typewriter-cursor { display: inline-block; width: 1ch; color: var(--secondary); animation: cursorBlink 1.1s ease-in-out infinite; }
    @keyframes cursorBlink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }
    .hero-subtitle { margin: 0; color: var(--text-muted); max-width: 62ch; font-size: 1.03rem; }
    .hero-actions { margin-top: 1.25rem; display: flex; flex-wrap: wrap; gap: 0.75rem; }
    .stats-grid { margin-top: 2rem; }
    .stat-card { padding: 1rem; }
    .stat-label { margin: 0 0 0.3rem; font-size: 0.95rem; color: var(--primary); font-weight: 700; }
    .stat-value { margin: 0; color: var(--text-muted); font-size: 0.98rem; }

    /* Hero entrance */
    @keyframes heroIn {
      from { opacity: 0; transform: translateY(32px); }
      to   { opacity: 1; transform: none; }
    }
    .hero-title { animation: heroIn var(--dur-slow) var(--ease-out) 0.05s both; }
    .hero-subtitle { animation: heroIn var(--dur-slow) var(--ease-out) 0.15s both; }
    .hero-actions { animation: heroIn var(--dur-slow) var(--ease-out) 0.25s both; }
    .stats-grid { animation: heroIn var(--dur-slow) var(--ease-out) 0.35s both; }

    @media (prefers-reduced-motion: reduce) {
      .hero-title,
      .hero-subtitle,
      .hero-actions,
      .stats-grid {
        animation: none !important;
      }
    }

    @media (max-width: 700px) {
    }

    .home-about-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 1rem;
      margin-top: 1.25rem;
    }

    .home-flow-grid {
      display: grid;
      grid-template-columns: repeat(4, minmax(0, 1fr));
      gap: 1rem;
      position: relative;
    }

    @media (max-width: 900px) {
      .home-about-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
      .home-flow-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    }

    @media (max-width: 600px) {
      .home-about-grid,
      .home-flow-grid { grid-template-columns: 1fr; }

      .section { padding: 3.5rem 0; }
      .hero { padding: 4.75rem 0 2.5rem; }
      .hero-actions a { flex: 1 1 100%; }
    }

    @media (max-width: 420px) {
      .hero-title { font-size: clamp(1.9rem, 8vw, 2.4rem); }
    }

    /* =========================================================
       Author Section
       ========================================================= */
    .author-section { padding-top: 1rem; }
    .team-wrap { margin-top: 1rem; padding: 1rem; }
    .member-card { padding: 1rem; border: 1px solid rgba(17,17,17,0.09); border-radius: 10px; background: linear-gradient(180deg,#ffffff,#f8faff); }
    .member-name { margin: 0; font-size: 1rem; color: var(--text-primary); }
    .member-nim { margin: 0.25rem 0 0; color: var(--primary); font-weight: 700; font-size: 0.95rem; }
    .member-subtitle { margin: 0.4rem 0 0; color: var(--text-muted); font-size: 0.9rem; }

    /* =========================================================
       PHASE 2 — MATERI
       ========================================================= */
    .tab-nav { display: flex; gap: 0.5rem; flex-wrap: wrap; border-bottom: 2px solid rgba(17,17,17,0.1); margin-bottom: 2rem; }
     .tab-btn { display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.7rem 1.1rem; border: none; border-bottom: 3px solid transparent; background: transparent; color: var(--text-muted); font-size: 0.97rem; font-weight: 600; cursor: pointer; border-radius: var(--radius-sm) var(--radius-sm) 0 0; transition: background-color 0.18s cubic-bezier(0.4, 0, 0.2, 1), color 0.18s cubic-bezier(0.4, 0, 0.2, 1); margin-bottom: -2px; }
    .tab-btn:hover { color: var(--primary); background: rgba(17,17,17,0.06); }
     .tab-btn.is-active { color: var(--primary); border-bottom-color: transparent; background: rgba(17,17,17,0.07); box-shadow: inset 0 3px 0 var(--secondary); }
     .tab-panel { display: none; opacity: 0; transform: translateX(-8px); transition: opacity 0.35s ease, transform 0.35s ease; }
     .tab-panel.is-active { display: block; opacity: 1; transform: translateX(0); }

    .oscilloscope-wrap { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 1.25rem; margin-bottom: 2rem; }
    @media (max-width: 700px) { .oscilloscope-wrap { grid-template-columns: 1fr; } }
    .osc-card { background: #0d1117; border-radius: var(--radius); overflow: hidden; border: 1px solid rgba(255,255,255,0.08); }
    .osc-label { padding: 0.55rem 0.85rem; font-size: 0.88rem; font-weight: 700; color: #c9d1d9; border-bottom: 1px solid rgba(255,255,255,0.07); letter-spacing: 0.03em; }
    .osc-canvas { width: 100%; height: 180px; display: block; }

    .table-wrap { overflow-x: auto; border-radius: var(--radius); box-shadow: var(--shadow); margin-bottom: 2rem; }
    .compare-table { width: 100%; border-collapse: collapse; font-size: 0.95rem; background: var(--surface); }
    .compare-table thead tr { background: linear-gradient(135deg,var(--primary),#2b2b2b); color: #fff; }
    .compare-table th, .compare-table td { padding: 0.75rem 1rem; text-align: left; border: 1px solid rgba(17,17,17,0.07); white-space: nowrap; }
    .compare-table th { font-weight: 700; font-size: 0.9rem; letter-spacing: 0.03em; }
    .compare-table th { padding: 0.85rem 1rem; }
    .compare-table tbody tr:nth-child(even) { background: rgba(17,17,17,0.025); }
    .compare-table tbody tr:hover { background: rgba(17,17,17,0.07); }
    .compare-table td:first-child { color: var(--primary); font-weight: 600; }
    .tag-ac { display: inline-block; padding: 0.15rem 0.5rem; border-radius: 6px; background: rgba(255,111,0,0.12); color: #c75c00; font-size: 0.88rem; font-weight: 700; }
    .tag-dc { display: inline-block; padding: 0.15rem 0.5rem; border-radius: 6px; background: rgba(16,185,129,0.12); color: #059669; font-size: 0.88rem; font-weight: 700; }

    .formula-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 1rem; margin-bottom: 2rem; }
    @media (max-width: 800px) { .formula-grid { grid-template-columns: 1fr; } }
    .formula-card { padding: 1.25rem; background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); }
    .formula-expr { margin: 0 0 0.75rem; font-size: 1.15rem; font-weight: 800; color: var(--primary); font-family: "Courier New",monospace; letter-spacing: 0.02em; }
    .formula-grid--black .formula-expr,
    .formula-grid--black .formula-vars li,
    .formula-grid--black .formula-vars li strong {
      color: #111111 !important;
    }
    .formula-vars { list-style: none; margin: 0; padding: 0; }
    .formula-vars li { font-size: 0.9rem; color: var(--text-muted); padding: 0.15rem 0; border-bottom: 1px dashed rgba(0,0,0,0.07); }
    .formula-vars li:last-child { border-bottom: none; }
    .formula-vars li strong { color: var(--text-primary); }

    .multimeter-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; align-items: start; margin-bottom: 2rem; }
    @media (max-width: 760px) { .multimeter-wrap { grid-template-columns: 1fr; } }
    .multimeter-diagram { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1rem; text-align: center; }
    .multimeter-diagram svg { width: 100%; max-width: 320px; height: auto; margin-inline: auto; }
    .multimeter-legend { margin-top: 0.75rem; display: flex; flex-direction: column; gap: 0.35rem; text-align: left; }
    .legend-row { display: flex; align-items: flex-start; gap: 0.55rem; }
    .legend-num { min-width: 22px; height: 22px; border-radius: 50%; color: #fff; font-weight: 700; font-size: 0.72rem; display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 1px; }
    .legend-text { display: flex; flex-direction: column; gap: 0.05rem; }
    .legend-text strong { font-size: 0.82rem; color: var(--text-primary); }
    .legend-text span { font-size: 0.76rem; color: var(--text-muted); }
    [data-tip] { position: relative; cursor: help; }
    .mm-hotspot:hover .mm-tooltip, .mm-hotspot:focus .mm-tooltip { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(-4px); }
    .mm-tooltip { pointer-events: none; position: absolute; bottom: calc(100% + 6px); left: 50%; transform: translateX(-50%) translateY(0); white-space: nowrap; background: #1a1a2e; color: #fff; font-size: 0.78rem; font-weight: 600; padding: 0.3rem 0.6rem; border-radius: 6px; opacity: 0; visibility: hidden; transition: var(--transition); z-index: 10; }
    .mm-tooltip::after { content: ""; position: absolute; top: 100%; left: 50%; transform: translateX(-50%); border: 5px solid transparent; border-top-color: #1a1a2e; }

    .calc-card { padding: 1.5rem; background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); }
    .calc-form { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 1rem; }
    @media (max-width: 600px) { .calc-form { grid-template-columns: 1fr; } }
    .form-group { display: flex; flex-direction: column; gap: 0.35rem; }
    .form-group label { font-size: 0.9rem; font-weight: 600; color: var(--text-primary); }
    .form-group select, .form-group input[type="range"] { padding: 0.6rem 0.75rem; border-radius: 8px; border: 1.5px solid rgba(17,17,17,0.2); font-size: 0.95rem; background: var(--background); color: var(--text-primary); outline: none; transition: border-color 0.2s; }
    .form-group select:focus { border-color: var(--primary); }
    .form-group input[type="range"] { padding: 0; cursor: pointer; accent-color: var(--primary); }
    .slider-val { font-size: 0.88rem; font-weight: 700; color: var(--primary); text-align: right; }
    .calc-result { margin-top: 1rem; padding: 1rem; border-radius: 10px; background: rgba(16,185,129,0.08); border: 1.5px solid rgba(16,185,129,0.3); transition: var(--transition); }
    .calc-result.is-error { background: rgba(239,68,68,0.08); border-color: rgba(239,68,68,0.3); }
    .calc-result .result-formula { margin: 0 0 0.5rem; font-family: "Courier New",monospace; font-size: 0.95rem; color: var(--text-primary); }
    .calc-result .result-main { margin: 0; font-size: 1.3rem; font-weight: 800; color: var(--success); }
    .calc-result.is-error .result-main { color: var(--danger); }

    /* =========================================================
       PHASE 3 — PROSEDUR
       ========================================================= */
    .proc-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; margin-bottom: 1.5rem; }
    @media (max-width: 700px) { .proc-columns { grid-template-columns: 1fr; } }
    .proc-block { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
    .proc-block-header { padding: 0.75rem 1rem; font-weight: 700; font-size: 0.95rem; color: #fff; display: flex; align-items: center; gap: 0.5rem; }
    .proc-block-header.ac { background: linear-gradient(135deg,#ff6f00,#ff9800); }
    .proc-block-header.dc { background: linear-gradient(135deg,var(--primary),#2b2b2b); }
    .proc-steps { list-style: none; margin: 0; padding: 0.75rem 1rem; }
    .proc-steps li { display: flex; align-items: flex-start; gap: 0.6rem; padding: 0.5rem 0; border-bottom: 1px dashed rgba(0,0,0,0.07); font-size: 0.93rem; color: var(--text-primary); }
    .proc-steps li:last-child { border-bottom: none; }
    .step-num { min-width: 22px; height: 22px; border-radius: 50%; background: var(--primary); color: #fff; font-size: 0.75rem; font-weight: 700; display: grid; place-items: center; flex-shrink: 0; margin-top: 1px; }
    .warning-card { display: flex; align-items: flex-start; gap: 0.75rem; padding: 0.9rem 1.1rem; border-radius: 10px; background: rgba(239,68,68,0.07); border: 1.5px solid rgba(239,68,68,0.25); font-size: 0.93rem; color: #b91c1c; font-weight: 600; }

    .safety-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; margin-bottom: 1.5rem; }
    @media (max-width: 700px) { .safety-columns { grid-template-columns: 1fr; } }
    .safety-block { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
    .safety-header { padding: 0.75rem 1rem; font-weight: 700; font-size: 0.95rem; color: #fff; }
    .safety-header.wajib { background: linear-gradient(135deg,var(--success),#059669); }
    .safety-header.dilarang { background: linear-gradient(135deg,var(--danger),#dc2626); }
    .safety-list { list-style: none; margin: 0; padding: 0.75rem 1rem; }
    .safety-list li { display: flex; align-items: flex-start; gap: 0.6rem; padding: 0.45rem 0; border-bottom: 1px dashed rgba(0,0,0,0.07); font-size: 0.92rem; color: var(--text-primary); }
    .safety-list li:last-child { border-bottom: none; }
    .safety-icon { font-size: 1rem; flex-shrink: 0; margin-top: 1px; }
    .apd-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 1rem; }
    @media (max-width: 600px) { .apd-grid { grid-template-columns: repeat(2,1fr); } }
    .apd-card { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1rem 0.75rem; text-align: center; border-top: 3px solid var(--primary); }
    .apd-emoji { font-size: 2rem; line-height: 1; margin-bottom: 0.4rem; }
    .apd-name { margin: 0; font-size: 0.88rem; font-weight: 700; color: var(--text-primary); }

    .stepper-block { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; margin-bottom: 2rem; }
    .stepper-header { padding: 1rem 1.25rem; background: linear-gradient(135deg,var(--primary),#2b2b2b); color: #fff; }
    .stepper-header.orange { background: linear-gradient(135deg,#ff6f00,#ff9800); }
    .stepper-header h3 { margin: 0 0 0.15rem; font-size: 1.05rem; }
    .stepper-header p { margin: 0; font-size: 0.88rem; opacity: 0.88; }
    .stepper-progress { padding: 0.75rem 1.25rem; background: rgba(17,17,17,0.04); border-bottom: 1px solid rgba(17,17,17,0.08); display: flex; align-items: center; gap: 1rem; }
    .stepper-progress-label { font-size: 0.88rem; font-weight: 700; color: var(--primary); white-space: nowrap; }
    .stepper-progress-bar { flex: 1; height: 6px; background: rgba(17,17,17,0.12); border-radius: 99px; overflow: hidden; }
    .stepper-progress-fill { height: 100%; background: linear-gradient(90deg,var(--primary),#3a3a3a); border-radius: 99px; transition: width 0.4s cubic-bezier(0.4,0,0.2,1); }
    .stepper-dots { display: flex; gap: 0.4rem; padding: 0.6rem 1.25rem; border-bottom: 1px solid rgba(17,17,17,0.06); overflow-x: auto; scrollbar-width: none; }
    .stepper-dots::-webkit-scrollbar { display: none; }
    .stepper-dot { flex-shrink: 0; width: 28px; height: 28px; border-radius: 50%; border: 2px solid rgba(17,17,17,0.2); background: var(--surface); color: var(--text-muted); font-size: 0.75rem; font-weight: 700; display: grid; place-items: center; transition: var(--transition); cursor: pointer; }
    .stepper-dot.is-done { background: var(--success); border-color: var(--success); color: #fff; }
    .stepper-dot.is-active { background: var(--primary); border-color: var(--primary); color: #fff; transform: scale(1.15); }
    .stepper-body { padding: 1.25rem; }
    .step-pane { display: none; }
    .step-pane.is-active { display: block; animation: stepFadeIn 0.3s ease; }
    @keyframes stepFadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
    .step-pane-icon { font-size: 2rem; margin-bottom: 0.4rem; display: block; }
    .step-pane h4 { margin: 0 0 0.5rem; color: var(--primary); font-size: 1rem; }
    .step-pane p { margin: 0 0 0.75rem; font-size: 0.95rem; color: var(--text-primary); line-height: 1.65; }
    .step-warning { display: flex; gap: 0.6rem; align-items: flex-start; padding: 0.7rem 0.9rem; background: rgba(239,68,68,0.07); border: 1.5px solid rgba(239,68,68,0.25); border-radius: 8px; font-size: 0.9rem; color: #b91c1c; font-weight: 600; margin-bottom: 0.75rem; }
    .step-success { display: flex; gap: 0.6rem; align-items: flex-start; padding: 0.7rem 0.9rem; background: rgba(16,185,129,0.07); border: 1.5px solid rgba(16,185,129,0.25); border-radius: 8px; font-size: 0.9rem; color: #065f46; font-weight: 600; margin-bottom: 0.75rem; }
    .stepper-actions { display: flex; justify-content: space-between; align-items: center; padding: 0.9rem 1.25rem; border-top: 1px solid rgba(17,17,17,0.08); gap: 0.5rem; }
    .circuit-svg-wrap { background: #f8faff; border-radius: 8px; border: 1px solid rgba(17,17,17,0.1); padding: 0.75rem; margin: 0.75rem 0; overflow-x: auto; }
    .circuit-svg-wrap svg { display: block; margin: 0 auto; max-width: 100%; }

    .obs-table-wrap { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; margin-bottom: 1.5rem; }
    .obs-table-header { padding: 0.85rem 1.1rem; display: flex; flex-wrap: wrap; gap: 0.75rem; align-items: center; justify-content: space-between; border-bottom: 1px solid rgba(17,17,17,0.08); }
    .obs-table-title { margin: 0; font-size: 1rem; font-weight: 700; color: var(--primary); }
    .obs-table-actions { display: flex; gap: 0.5rem; }
    .btn-table { display: inline-flex; align-items: center; gap: 0.35rem; padding: 0.45rem 0.85rem; border-radius: 8px; font-size: 0.85rem; font-weight: 600; border: 1.5px solid transparent; cursor: pointer; transition: var(--transition); }
    .btn-table.reset { color: var(--danger); border-color: rgba(239,68,68,0.3); background: rgba(239,68,68,0.06); }
    .btn-table.reset:hover { background: rgba(239,68,68,0.14); }
    .btn-table.print { color: var(--primary); border-color: rgba(17,17,17,0.25); background: rgba(17,17,17,0.05); }
    .btn-table.print:hover { background: rgba(17,17,17,0.12); }
    .obs-scroll { overflow-x: auto; }
    .obs-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; min-width: 620px; }
    .obs-table thead tr { background: linear-gradient(135deg,var(--primary),#2b2b2b); color: #fff; }
    .obs-table-wrap--orange .obs-table thead tr { background: linear-gradient(135deg,#ff6f00,#ff9800); }
    .obs-table th { padding: 0.65rem 0.8rem; font-size: 0.82rem; font-weight: 700; letter-spacing: 0.02em; text-align: left; white-space: nowrap; border: 1px solid rgba(17,17,17,0.07); }
    .obs-table td { padding: 0.5rem 0.8rem; border: 1px solid rgba(17,17,17,0.07); color: var(--text-primary); vertical-align: middle; }
    .obs-table tbody tr:hover, .obs-table tbody tr:focus-within { background: rgba(17,17,17,0.06); }
    .obs-table tbody tr:nth-child(even) { background: rgba(17,17,17,0.025); }
    .obs-table tbody tr:nth-child(even):hover, .obs-table tbody tr:nth-child(even):focus-within { background: rgba(17,17,17,0.06); }
    .obs-table tbody tr:focus-within { box-shadow: inset 0 0 0 2px rgba(17,17,17,0.14); }
    .obs-table .cell-no { width: 40px; text-align: center; font-weight: 700; color: var(--text-muted); }
    .obs-table .cell-fixed { color: var(--text-muted); font-size: 0.88rem; }
    .obs-table .cell-auto { color: var(--primary); font-weight: 700; font-size: 0.9rem; }
    .obs-input { width: 100%; min-width: 72px; padding: 0.35rem 0.55rem; border: 1.5px solid rgba(17,17,17,0.15); border-radius: 6px; font-size: 0.9rem; font-family: inherit; background: var(--background); color: var(--text-primary); outline: none; transition: border-color 0.2s, box-shadow 0.2s; }
    .obs-input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(17,17,17,0.1); }
    .obs-input.is-valid { border-color: var(--success); }
    .obs-input.is-error { border-color: var(--danger); background: rgba(239,68,68,0.04); }

    @media print {
      .scroll-progress, .loader-screen, .site-header, .hero, .author-section, #materi, #simulasi, #kuis, .stepper-block, .stepper-actions, .obs-table-actions, .site-footer { display: none !important; }
      body { background: #fff; font-size: 11pt; }
      #prosedur { padding: 0 !important; }
      .obs-table-wrap { box-shadow: none; border: 1px solid #ccc; break-inside: avoid; margin-bottom: 1.5rem; }
      .obs-table thead tr { background: #111111 !important; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
      .obs-input { border: 1px solid #aaa; background: #fff; }
    }

    /* =========================================================
       PHASE 4 — SIMULASI
       ========================================================= */
    .sim-block { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; margin-bottom: 2rem; }
    .sim-header { padding: 0.9rem 1.25rem; display: flex; align-items: center; gap: 0.65rem; border-bottom: 1px solid rgba(17,17,17,0.08); }
    .sim-header h3 { margin: 0; font-size: 1rem; color: var(--primary); }
    .sim-body { padding: 1.25rem; }
    .meter-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; align-items: start; }
    @media (max-width: 820px) { .meter-layout { grid-template-columns: 1fr; } }
    .meter-canvas-wrap { text-align: center; }
    #meterCanvas { width: 100%; max-width: 420px; height: auto; border-radius: 12px; border: 3px solid #2c2f3f; box-shadow: 0 8px 28px rgba(0,0,0,0.18); background: #fafafa; }
    .batas-row { display: flex; gap: 0.5rem; justify-content: center; flex-wrap: wrap; margin-top: 0.75rem; }
    .batas-btn { padding: 0.4rem 0.9rem; border-radius: 8px; border: 1.5px solid rgba(17,17,17,0.25); background: transparent; color: var(--primary); font-weight: 700; font-size: 0.88rem; cursor: pointer; transition: var(--transition); }
    .batas-btn.active, .batas-btn:hover { background: var(--primary); color: #fff; border-color: var(--primary); }
    .game-panel { display: flex; flex-direction: column; gap: 1rem; }
    .scoreboard { display: grid; grid-template-columns: repeat(3,1fr); gap: 0.5rem; }
    .score-card { background: var(--background); border-radius: 8px; padding: 0.6rem; text-align: center; }
    .score-card-val { margin: 0; font-size: 1.35rem; font-weight: 800; color: var(--primary); }
    .score-card-lbl { margin: 0; font-size: 0.78rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
    .game-input-row { display: flex; gap: 0.6rem; align-items: center; }
    .game-input { flex: 1; padding: 0.6rem 0.8rem; border: 1.5px solid rgba(17,17,17,0.2); border-radius: 8px; font-size: 1rem; font-family: inherit; outline: none; transition: border-color 0.2s; }
    .game-input:focus { border-color: var(--primary); }
    .feedback-card { min-height: 48px; padding: 0.65rem 0.9rem; border-radius: 10px; font-weight: 600; font-size: 0.93rem; transition: background 0.3s, border-color 0.3s; border: 1.5px solid transparent; display: flex; align-items: center; gap: 0.5rem; }
    .feedback-card.correct { background: rgba(16,185,129,0.1); border-color: rgba(16,185,129,0.35); border-left: 4px solid var(--success); color: #065f46; }
    .feedback-card.wrong { background: rgba(239,68,68,0.08); border-color: rgba(239,68,68,0.3); border-left: 4px solid var(--danger); color: #b91c1c; }
    .feedback-card.neutral { background: rgba(17,17,17,0.04); border-color: rgba(17,17,17,0.1); color: var(--text-muted); }
    .result-modal-overlay { position: fixed; inset: 0; z-index: 1300; background: rgba(10,15,30,0.72); display: grid; place-items: center; padding: 1rem; opacity: 0; visibility: hidden; transition: opacity 0.3s ease, visibility 0.3s ease; }
    .result-modal-overlay.is-visible { opacity: 1; visibility: visible; }
    .result-modal { background: var(--surface); border-radius: 16px; box-shadow: 0 20px 60px rgba(0,0,0,0.25); padding: 2rem; max-width: 400px; width: 100%; text-align: center; transform: scale(0.92); transition: transform 0.3s ease; }
    .result-modal-overlay.is-visible .result-modal { transform: scale(1); }
    .result-modal-emoji { font-size: 3rem; display: block; margin-bottom: 0.5rem; }
    .result-modal-title { margin: 0 0 0.35rem; font-size: 1.3rem; color: var(--primary); }
    .result-modal-sub { margin: 0 0 1.5rem; color: var(--text-muted); font-size: 0.95rem; }
    .cro-layout { display: grid; grid-template-columns: 1fr 200px; gap: 1rem; align-items: start; }
    @media (max-width: 760px) { .cro-layout { grid-template-columns: 1fr; } }
    .cro-screen-wrap { background: #0a0f1e; border-radius: 10px; padding: 6px; border: 6px solid #2a2f3f; box-shadow: inset 0 0 24px rgba(0,0,0,0.6), 0 6px 20px rgba(0,0,0,0.3); }
    #croCanvas { display: block; width: 100%; border-radius: 6px; background: #0a0f1e; }
    .cro-controls { background: #1e2436; border-radius: 10px; padding: 1rem; display: flex; flex-direction: column; gap: 0.75rem; }
    .ctrl-label { display: block; font-size: 0.75rem; font-weight: 700; color: #8899aa; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 0.25rem; }
    .ctrl-group { display: flex; flex-direction: column; gap: 0.2rem; }
    .ctrl-group input[type="range"] { width: 100%; accent-color: #39ff7a; cursor: pointer; }
    .ctrl-group select { width: 100%; padding: 0.35rem 0.5rem; border-radius: 6px; border: 1px solid #3a4060; background: #12172a; color: #c8d6e0; font-size: 0.85rem; outline: none; }
    .coupling-btns { display: flex; gap: 0.4rem; }
    .coupling-btn { flex: 1; padding: 0.35rem; border-radius: 6px; border: 1px solid #3a4060; background: #12172a; color: #8899aa; font-size: 0.85rem; font-weight: 700; cursor: pointer; transition: var(--transition); }
    .coupling-btn.active { background: #1a3a2a; border-color: #39ff7a; color: #39ff7a; }
    .cro-btn { width: 100%; padding: 0.45rem; border-radius: 6px; border: 1px solid #3a4060; background: #12172a; color: #c8d6e0; font-size: 0.85rem; font-weight: 700; cursor: pointer; transition: var(--transition); }
    .cro-btn:hover { background: rgba(255,255,255,0.06); border-color: rgba(255,255,255,0.22); }
    .cro-btn.running { border-color: #39ff7a; color: #39ff7a; }
    .vpos-btns { display: flex; gap: 0.4rem; }
    .vpos-btn { flex: 1; padding: 0.35rem; border-radius: 6px; border: 1px solid #3a4060; background: #12172a; color: #c8d6e0; font-size: 0.9rem; font-weight: 700; cursor: pointer; transition: var(--transition); }
    .vpos-btn:hover { background: rgba(255,255,255,0.06); }
    .cro-readout { background: #0a1208; border-radius: 10px; border: 1px solid #1a3020; padding: 0.85rem 1rem; font-family: "Courier New",monospace; display: flex; flex-direction: column; gap: 0.4rem; }
    .readout-title { font-size: 0.7rem; font-weight: 700; color: #2a5a3a; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 0.2rem; }
    .readout-row { display: flex; justify-content: space-between; align-items: baseline; gap: 0.5rem; }
    .readout-key { font-size: 0.8rem; color: #3a7a50; }
    .readout-val { font-size: 0.92rem; font-weight: 700; color: #39ff7a; letter-spacing: 0.03em; }
    .cro-panel-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 0.75rem; margin-top: 0.75rem; }
    @media (max-width: 600px) { .cro-panel-row { grid-template-columns: 1fr 1fr; } }

    /* =========================================================
       PHASE 5 — QUIZ
       ========================================================= */
    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(24px) scale(0.98); }
      to   { opacity: 1; transform: translateY(0) scale(1); }
    }
    .back-to-top { position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 990; width: 44px; height: 44px; border-radius: 50%; background: var(--primary); color: #fff; border: none; font-size: 1.1rem; cursor: pointer; box-shadow: 0 4px 16px rgba(17,17,17,0.3); transition: var(--transition); opacity: 0; visibility: hidden; display: grid; place-items: center; }
    .back-to-top.is-visible { opacity: 1; visibility: visible; }
    .back-to-top:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(17,17,17,0.4); }
    .quiz-screen { display: none; }
    .quiz-screen.is-active { display: block; animation: fadeInUp 0.4s ease forwards; }
    .pre-quiz-card { max-width: 520px; margin: 0 auto; padding: 2rem; text-align: center; }
    .pre-quiz-icon { font-size: 3rem; margin-bottom: 0.5rem; display: block; }
    .pre-quiz-rules { list-style: none; margin: 1rem 0 1.5rem; padding: 0; text-align: left; display: inline-block; }
    .pre-quiz-rules li { display: flex; gap: 0.6rem; align-items: flex-start; padding: 0.35rem 0; font-size: 0.95rem; color: var(--text-primary); }
    .pre-quiz-note { margin: 1rem 0 0; font-size: 0.85rem; color: var(--text-muted); }

    .quiz-field { margin: 1rem auto 1.25rem; max-width: 360px; text-align: left; }
    .quiz-field label { display: block; font-size: 0.9rem; font-weight: 700; color: var(--text-primary); margin-bottom: 0.4rem; }
    .quiz-input {
      width: 100%;
      padding: 0.65rem 0.75rem;
      border-radius: 10px;
      border: 1.5px solid rgba(17,17,17,0.18);
      background: var(--background);
      color: var(--text-primary);
      font-size: 0.95rem;
      outline: none;
      transition: border-color 0.2s, box-shadow 0.2s;
    }
    .quiz-input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(17,17,17,0.10); }
    .quiz-field-note { margin: 0.5rem 0 0; font-size: 0.82rem; color: var(--text-muted); }
    .quiz-top-bar { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 0.75rem; margin-bottom: 1.25rem; }
    .quiz-progress-wrap { flex: 1; min-width: 120px; }
    .quiz-progress-bar { height: 6px; background: rgba(17,17,17,0.1); border-radius: 99px; overflow: hidden; margin-top: 4px; }
    .quiz-progress-fill { height: 100%; background: linear-gradient(90deg,var(--primary),#3a3a3a); border-radius: 99px; transition: width 300ms var(--ease-out); }
    .quiz-timer { font-size: 1.15rem; font-weight: 800; color: var(--primary); font-family: "Courier New",monospace; transition: color 0.3s; }
    .quiz-timer.urgent { color: var(--danger); background: rgba(239,68,68,0.08); border-radius: var(--radius-sm); padding: 0.2rem 0.55rem; animation: timerPulse 0.8s ease-in-out infinite; }
    @keyframes timerPulse { 0%,100% { opacity: 1; } 50% { opacity: 0.45; } }
    .q-card { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1.5rem; margin-bottom: 1rem; }
    .q-badge { display: inline-flex; align-items: center; gap: 0.4rem; padding: 0.25rem 0.65rem; border-radius: 999px; background: rgba(17,17,17,0.08); color: var(--primary); font-size: 0.82rem; font-weight: 700; margin-bottom: 0.75rem; }
    .q-text { margin: 0; font-size: 1.03rem; line-height: 1.65; color: var(--text-primary); }
    .q-options { display: flex; flex-direction: column; gap: 0.55rem; margin-top: 1.25rem; }
    .q-option { display: flex; align-items: center; gap: 0.75rem; padding: 0.7rem 1rem; border-radius: 10px; border: 1.5px solid rgba(17,17,17,0.14); background: var(--background); color: var(--text-primary); font-size: 0.95rem; text-align: left; cursor: pointer; transition: var(--transition); }
    .q-option:hover:not(:disabled) { border-color: var(--primary); background: rgba(17,17,17,0.06); transform: translateX(4px); box-shadow: inset 3px 0 0 var(--primary); }
    .q-option .opt-label { min-width: 26px; height: 26px; border-radius: 50%; background: rgba(17,17,17,0.1); color: var(--primary); font-weight: 800; font-size: 0.8rem; display: grid; place-items: center; flex-shrink: 0; transition: var(--transition); }
    .q-option:disabled { cursor: default; }
    .q-option.is-correct { border-color: var(--success); background: rgba(16,185,129,0.09); color: #065f46; }
    .q-option.is-correct .opt-label { background: var(--success); color: #fff; }
    .q-option.is-wrong { border-color: var(--danger); background: rgba(239,68,68,0.07); color: #b91c1c; }
    .q-option.is-wrong .opt-label { background: var(--danger); color: #fff; }
    .q-next-btn { display: none; width: 100%; margin-top: 0.75rem; }
    .q-next-btn.is-visible { display: block; }

    .result-user { font-size: 0.95rem; }
    .result-note { margin: 1rem 0 0; font-size: 0.82rem; color: var(--text-muted); line-height: 1.5; }
    .result-score-circle { width: 120px; height: 120px; border-radius: 50%; background: linear-gradient(135deg,var(--primary),#3a3a3a); margin: 0 auto 1rem; display: grid; place-items: center; box-shadow: 0 0 0 8px rgba(17,17,17,0.12); position: relative; }
    .result-score-circle::after {
      content: "";
      position: absolute;
      inset: -10px;
      border-radius: 50%;
      border: 2px solid rgba(17,17,17,0.22);
      animation: scoreRingPulse 1.8s ease-in-out infinite;
      pointer-events: none;
    }
    @keyframes scoreRingPulse {
      0% { transform: scale(1); opacity: 0.6; }
      50% { transform: scale(1.06); opacity: 0.22; }
      100% { transform: scale(1); opacity: 0.6; }
    }
    .result-score-val { font-size: 2rem; font-weight: 900; color: #fff; }
    .grade-badge { display: inline-flex; align-items: center; justify-content: center; min-width: 120px; padding: 0.45rem 1rem; border-radius: 999px; font-size: 1rem; font-weight: 800; letter-spacing: 0.04em; margin-bottom: 1rem; }
    .grade-A { background: rgba(16,185,129,0.15); color: #065f46; box-shadow: 0 0 16px rgba(16,185,129,0.3); }
    .grade-B { background: rgba(17,17,17,0.12); color: var(--primary); box-shadow: 0 0 16px rgba(17,17,17,0.2); }
    .grade-C { background: rgba(251,191,36,0.15); color: #92400e; box-shadow: 0 0 16px rgba(251,191,36,0.25); }
    .grade-D { background: rgba(239,68,68,0.10); color: #b91c1c; box-shadow: 0 0 16px rgba(239,68,68,0.2); }
    .result-stats { display: flex; justify-content: center; gap: 1.5rem; flex-wrap: wrap; margin-bottom: 1.5rem; }
    .result-stat-item { text-align: center; }
    .result-stat-val { font-size: 1.5rem; font-weight: 800; color: var(--primary); }
    .result-stat-lbl { font-size: 0.8rem; color: var(--text-muted); text-transform: uppercase; }
    .review-accordion { border: 1px solid rgba(17,17,17,0.1); border-radius: var(--radius); overflow: hidden; margin-top: 1.5rem; margin-bottom: 1.5rem; }
    .review-accordion-title { font-size: 0.95rem; font-weight: 700; color: var(--primary); padding: 0.75rem 1rem; background: rgba(17,17,17,0.05); border-bottom: 1px solid rgba(17,17,17,0.1); margin: 0; }
    .review-item { border-bottom: 1px solid rgba(17,17,17,0.06); }
    .review-item:last-child { border-bottom: none; }
    .review-toggle { width: 100%; text-align: left; padding: 0.7rem 1rem; background: transparent; border: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 0.5rem; font-size: 0.9rem; color: var(--text-primary); transition: background 0.2s; }
    .review-toggle:hover { background: rgba(17,17,17,0.04); }
    .review-toggle .r-icon { font-size: 0.85rem; transition: transform 0.25s; flex-shrink: 0; }
    .review-toggle.open .r-icon { transform: rotate(180deg); }
    .review-detail { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; background: rgba(17,17,17,0.02); }
    .review-detail.open { max-height: 320px; }
    .review-detail-inner { padding: 0.75rem 1rem 1rem; font-size: 0.9rem; }
    .r-label { font-weight: 700; color: var(--text-muted); font-size: 0.8rem; text-transform: uppercase; }
    .r-correct { color: #065f46; font-weight: 700; }
    .r-wrong { color: #b91c1c; font-weight: 700; }
    .r-explain { margin-top: 0.4rem; color: var(--text-muted); font-style: italic; }
    .result-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; justify-content: center; }

    /* =========================================================
       FOOTER — BERSIH TANPA DUPLIKAT
       ========================================================= */
    .site-footer {
      padding: 0;
      background: #0d1117;
      color: #c9d1d9;
      font-size: 0.9rem;
      position: relative;
      border-top: 1px solid transparent;
      background-clip: padding-box;
    }

    .site-footer::before {
      content: "";
      position: absolute;
      left: 0;
      right: 0;
      top: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(79, 99, 210, 0.60), rgba(255, 157, 63, 0.55), transparent);
      pointer-events: none;
    }

    .footer-main {
      padding: 2.5rem 0 2rem;
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 3rem;
      align-items: start;
    }

    @media (max-width: 640px) {
      .footer-main { grid-template-columns: 1fr; gap: 2rem; }
    }

    .footer-brand {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 800;
      font-size: 1.05rem;
      color: #e2e8f0;
      margin-bottom: 0.75rem;
    }

    .footer-brand svg { width: 20px; height: 20px; color: var(--secondary); }

    .footer-desc {
      display: flex;
      flex-direction: column;
      gap: 0.4rem;
      margin: 0;
    }

    .footer-row {
      display: grid;
      grid-template-columns: 18px 108px 10px 1fr;
      align-items: baseline;
      column-gap: 0.35rem;
      font-size: 0.875rem;
      line-height: 1.6;
    }

    .footer-row i {
      color: #ff9d3f;
      font-size: 0.75rem;
      margin: 0;
    }

    .footer-key {
      color: #c9d1d9;
      font-weight: 600;
      white-space: nowrap;
    }

    .footer-sep {
      color: #6e7681;
      justify-self: center;
    }

    .footer-val {
      color: #8b949e;
    }

    .footer-col-title {
      font-size: 0.82rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: #8b949e;
      margin: 0 0 0.75rem;
    }

    .footer-team-list {
      list-style: none;
      margin: 0;
      padding: 0;
      display: flex;
      flex-direction: column;
    }

    .footer-team-list li {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 0.9rem;
      color: #c9d1d9;
      padding: 0.4rem 0;
      border-bottom: 1px solid rgba(255,255,255,0.05);
      border-radius: var(--radius-sm);
      transition: var(--transition-fast);
    }

    .footer-team-list li:hover {
      background: rgba(255,255,255,0.04);
      transform: translateX(3px);
    }

    .footer-team-list li:last-child { border-bottom: none; }

    .footer-nim {
      background: rgba(255,255,255,0.06);
      padding: 0.15rem 0.5rem;
      border-radius: 4px;
      font-family: "Courier New", monospace;
      font-size: 0.82rem;
      color: #8b949e;
    }

    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.07);
      padding: 1rem 0;
      text-align: center;
      font-size: 0.82rem;
      color: #6e7681;
    }

    /* Font Awesome spacing */
    .fas, .far, .fab { margin-right: 6px; font-size: 0.95em; }
    .footer-row .fas,
    .footer-row .far,
    .footer-row .fab { margin-right: 0; }

    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }

      .reveal,
      .reveal.is-visible {
        animation: none !important;
        transform: none !important;
        opacity: 1 !important;
      }

      .card:hover,
      .stat-card:hover,
      .member-card:hover,
      .formula-card:hover,
      .apd-card:hover,
      .btn-primary:hover,
      .btn-secondary:hover,
      .back-to-top:hover,
      .q-option:hover:not(:disabled) {
        transform: none !important;
      }

      .result-score-circle::after,
      .quiz-timer.urgent,
      .typewriter-cursor {
        animation: none !important;
      }
    }

/* ─── Brand / Loader / Hero logos ──────────────────────────── */
.brand-logo {
  height: 40px;
  width: auto;
  object-fit: contain;
}

.loader-logo {
  width: 80px;
  height: 80px;
  object-fit: contain;
  margin: 0 auto 0.75rem;
  opacity: 0;
  animation: fadeInBrand 1.1s ease forwards;
}

.hero-logo {
  width: 72px;
  height: 72px;
  object-fit: contain;
  margin-bottom: 1rem;
}

/* ─── Member avatar ─────────────────────────────────────────── */
.member-card {
  text-align: center;
}

.member-avatar-wrap {
  width: 120px;
  height: 120px;
  border-radius: 25%;
  overflow: hidden;
  margin: 0 auto 0.75rem;
  border: 3px solid rgba(17,17,17,0.15);
  box-shadow: 0 4px 12px rgba(17,17,17,0.12);
}

.member-avatar {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 50%;
  transform: scale(1.15);
  transform-origin: center 50%;
}

/* Adjust crop for specific portraits (move focus upward) */
.member-avatar.member-avatar--up {
  object-position: center 50%;
}

/* ─── Footer logo ───────────────────────────────────────────── */
.footer-logo {
  height: 36px;
  width: auto;
  object-fit: contain;
}

/* =========================================================
   SCENARIO BUTTONS (Simulasi Kesalahan)
   ========================================================= */
.scenario-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 1.5rem;
  background: #f9f9f9;
  border: 2px solid #e5e5e5;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
  font-size: 14px;
  font-weight: 600;
  color: #666;
  min-height: 140px;
}

.scenario-btn:hover {
  border-color: #ff6f00;
  background: #fff8f0;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(255, 111, 0, 0.15);
}

.scenario-btn.is-active {
  background: linear-gradient(135deg, #ff6f00, #ff9800);
  border-color: #ff6f00;
  color: white;
  box-shadow: 0 6px 16px rgba(255, 111, 0, 0.3);
}

.scenario-btn i {
  font-size: 32px;
}

/* =========================================================
   GLOBAL SEARCH (Ctrl+K)
   ========================================================= */
.global-search-btn {
  margin-left: 0.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.55rem 0.85rem;
  border: 1px solid rgba(17,17,17,0.18);
  background: rgba(255,255,255,0.92);
  color: var(--text-primary);
  border-radius: 12px;
  cursor: pointer;
  transition: var(--transition-fast);
  white-space: nowrap;
}

.global-search-btn:hover {
  background: #fff;
  border-color: rgba(17,17,17,0.28);
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.08);
}

.global-search-btn .label {
  font-weight: 700;
  font-size: 0.95rem;
}

.global-search-btn .kbd {
  font-size: 0.75rem;
  color: var(--text-muted);
  padding: 0.12rem 0.4rem;
  border: 1px solid rgba(17,17,17,0.16);
  border-radius: 8px;
  background: rgba(255,255,255,0.75);
}

@media (max-width: 900px) {
  .global-search-btn .label,
  .global-search-btn .kbd {
    display: none;
  }
  .global-search-btn {
    padding: 0.55rem 0.7rem;
    border-radius: 10px;
  }
}

.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.55);
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: calc(var(--header-height) + 22px) 16px 16px;
  z-index: 9999;
}

.search-overlay.is-open {
  display: flex;
}

.search-modal {
  width: min(760px, 100%);
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 18px 60px rgba(0,0,0,0.30);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.12);
}

.search-modal-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 14px 16px;
  border-bottom: 1px solid rgba(17,17,17,0.10);
}

.search-input {
  flex: 1;
  width: 100%;
  border: 1px solid rgba(17,17,17,0.16);
  border-radius: 12px;
  padding: 11px 12px;
  font-size: 1rem;
  outline: none;
}

.search-input:focus {
  border-color: rgba(255,111,0,0.55);
  box-shadow: 0 0 0 4px rgba(255,111,0,0.12);
}

.search-close {
  border: 1px solid rgba(17,17,17,0.16);
  background: rgba(17,17,17,0.06);
  color: var(--text-primary);
  border-radius: 10px;
  padding: 0.45rem 0.6rem;
  cursor: pointer;
  font-weight: 700;
  font-size: 0.85rem;
}

.search-results {
  max-height: 380px;
  overflow: auto;
}

.search-item {
  width: 100%;
  text-align: left;
  padding: 12px 16px;
  background: #fff;
  border: 0;
  border-bottom: 1px solid rgba(17,17,17,0.06);
  cursor: pointer;
}

.search-item:hover,
.search-item:focus-visible {
  background: rgba(17,17,17,0.06);
  outline: none;
}

.search-item-title {
  font-weight: 800;
  color: var(--text-primary);
}

.search-item-desc {
  margin-top: 2px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.search-empty {
  padding: 16px;
  color: var(--text-muted);
}

.search-hint {
  padding: 10px 16px;
  background: rgba(17,17,17,0.04);
  color: var(--text-muted);
  font-size: 0.85rem;
}

@media (prefers-reduced-motion: reduce) {
  .global-search-btn,
  .scenario-btn {
    transition: none !important;
  }
  .global-search-btn:hover,
  .scenario-btn:hover {
    transform: none !important;
  }
}