/* === BASE STYLES === */:root {
      --color-1: #0a0e1a;
      --color-2: #0d1b2e;
      --color-3: #0a2a3d;
      --color-4: #00e5ff;
      --color-5: #00b8d9;
      --color-6: #ffffff;
      --color-7: #b0c4d8;
      --color-8: #1a2f45;
      --color-9: #00e5ff22;
      --color-10: #0a1520;
      --space-1: 0.5rem;
      --space-2: 1rem;
      --space-3: 1.5rem;
      --space-4: 2rem;
      --space-5: 3rem;
      --space-6: 5rem;
      --radius-1: 8px;
      --radius-2: 16px;
      --radius-3: 24px;
      --font-main: 'Segoe UI', system-ui, -apple-system, sans-serif;
      --shadow-1: 0 4px 24px rgba(0,229,255,0.10);
      --shadow-2: 0 8px 40px rgba(0,229,255,0.18);
      --shadow-3: 0 2px 12px rgba(0,0,0,0.5);
      --transition-1: all 0.3s cubic-bezier(0.4,0,0.2,1);
    }

    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

    html, body {
      overflow-x: hidden;
      max-width: 100vw;
      font-family: var(--font-main);
      background-color: var(--color-1);
      color: var(--color-6);
      scroll-behavior: smooth;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 var(--space-3);
    }

    .btn-primary {
      display: inline-block;
      background: linear-gradient(135deg, var(--color-4) 0%, var(--color-5) 100%);
      color: var(--color-1) !important;
      font-weight: 700;
      font-size: 1rem;
      padding: 0.75rem 2rem;
      border-radius: 50px;
      text-decoration: none;
      border: none;
      cursor: pointer;
      transition: var(--transition-1);
      box-shadow: 0 0 24px rgba(0,229,255,0.35), 0 4px 16px rgba(0,0,0,0.3);
      letter-spacing: 0.04em;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .btn-primary::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(255,255,255,0.18) 0%, transparent 60%);
      opacity: 0;
      transition: opacity 0.3s;
    }
    .btn-primary:hover {
      transform: translateY(-2px) scale(1.04);
      box-shadow: 0 0 40px rgba(0,229,255,0.55), 0 8px 32px rgba(0,0,0,0.4);
      color: var(--color-1) !important;
      text-decoration: none;
    }
    .btn-primary:hover::after { opacity: 1; }
    .btn-primary:active { transform: scale(0.98); }

    .section-wrapper {
      padding: var(--space-6) 0;
    }
    .section-wrapper:nth-child(even) {
      background: var(--color-2);
    }

    figure.content-image {
      margin: var(--space-4) 0;
      border-radius: var(--radius-2);
      overflow: hidden;
      box-shadow: var(--shadow-2);
    }
    figure.content-image img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: cover;
      max-height: 420px;
    }
    figure.content-image.wide img { max-height: 480px; }

    .card {
      background: linear-gradient(145deg, var(--color-8) 0%, var(--color-2) 100%);
      border: 1px solid rgba(0,229,255,0.13);
      border-radius: var(--radius-2);
      padding: var(--space-4);
      box-shadow: var(--shadow-1);
      transition: var(--transition-1);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-2);
      border-color: rgba(0,229,255,0.3);
    }

    .info-card {
      background: linear-gradient(145deg, var(--color-8) 0%, var(--color-2) 100%);
      border: 1px solid rgba(0,229,255,0.15);
      border-radius: var(--radius-2);
      padding: var(--space-3) var(--space-4);
      box-shadow: var(--shadow-1);
    }
    .info-card h3 {
      color: var(--color-4);
      font-size: 1.1rem;
      margin-bottom: var(--space-1);
    }
    .info-card p, .info-card a {
      color: var(--color-7);
      font-size: 0.97rem;
    }
    .info-card a:hover { color: var(--color-4); }

    a { color: var(--color-4); text-decoration: none; transition: color 0.2s; }
    a:hover { color: var(--color-5); }

    h2 {
      font-size: clamp(1.6rem, 3.5vw, 2.4rem);
      font-weight: 800;
      margin-bottom: var(--space-3);
      color: var(--color-6);
      letter-spacing: -0.01em;
    }
    h3 { font-size: 1.15rem; font-weight: 700; color: var(--color-4); margin-bottom: var(--space-1); }
    p { color: var(--color-7); line-height: 1.75; margin-bottom: var(--space-2); font-size: 1rem; }
    p:last-child { margin-bottom: 0; }

    .section-label {
      font-size: 0.78rem;
      font-weight: 700;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--color-4);
      margin-bottom: var(--space-2);
      display: block;
    }

    .divider-line {
      width: 60px;
      height: 3px;
      background: linear-gradient(90deg, var(--color-4), var(--color-5));
      border-radius: 2px;
      margin-bottom: var(--space-3);
    }

    /* table-responsive */
    .table-responsive {
      overflow-x: auto;
      border-radius: var(--radius-2);
      border: 1px solid rgba(0,229,255,0.13);
      margin: var(--space-3) 0;
    }
    .feature-table {
      width: 100%;
      border-collapse: collapse;
      background: var(--color-2);
      min-width: 320px;
    }
    .feature-table thead tr {
      background: linear-gradient(90deg, var(--color-3) 0%, var(--color-8) 100%);
    }
    .feature-table th {
      padding: 1rem 1.5rem;
      text-align: left;
      color: var(--color-4);
      font-weight: 700;
      font-size: 0.9rem;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      border-bottom: 2px solid rgba(0,229,255,0.2);
    }
    .feature-table tbody tr {
      border-bottom: 1px solid rgba(0,229,255,0.08);
      transition: background 0.2s;
    }
    .feature-table tbody tr:hover { background: rgba(0,229,255,0.05); }
    .feature-table td {
      padding: 1rem 1.5rem;
      color: var(--color-7);
      font-size: 0.97rem;
    }
    .feature-table td strong { color: var(--color-6); }

    /* accordion */
    .accordion-item {
      background: var(--color-2);
      border: 1px solid rgba(0,229,255,0.12);
      border-radius: var(--radius-1) !important;
      margin-bottom: var(--space-2);
      overflow: hidden;
    }
    .accordion-header button {
      width: 100%;
      text-align: left;
      background: transparent;
      border: none;
      padding: 1.1rem 1.5rem;
      color: var(--color-6);
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 1rem;
      transition: color 0.2s;
    }
    .accordion-header button:hover { color: var(--color-4); }
    .accordion-header button::after {
      content: '+';
      font-size: 1.4rem;
      color: var(--color-4);
      font-weight: 300;
      flex-shrink: 0;
      transition: transform 0.3s;
    }
    .accordion-header button[aria-expanded="true"] { color: var(--color-4); }
    .accordion-header button[aria-expanded="true"]::after { content: '−'; transform: rotate(0deg); }
    .accordion-body {
      display: none;
      padding: 0 1.5rem 1.2rem;
    }
    .accordion-body.open { display: block; }
    .accordion-body p { color: var(--color-7); margin-bottom: 0; }

    /* highlight box */
    .highlight-box {
      background: linear-gradient(145deg, var(--color-8) 0%, var(--color-10) 100%);
      border: 1px solid rgba(0,229,255,0.15);
      border-radius: var(--radius-2);
      padding: var(--space-3);
      box-shadow: var(--shadow-1);
      transition: var(--transition-1);
    }
    .highlight-box:hover {
      border-color: rgba(0,229,255,0.35);
      transform: translateY(-3px);
      box-shadow: var(--shadow-2);
    }
    .highlight-box h3 { color: var(--color-4); margin-bottom: var(--space-1); }
    .highlight-box p { color: var(--color-7); font-size: 0.95rem; }
    .highlight-box figure { margin: var(--space-2) 0 0; }

    /* feature block */
    .feature-block {
      background: linear-gradient(145deg, var(--color-8) 0%, var(--color-2) 100%);
      border: 1px solid rgba(0,229,255,0.12);
      border-radius: var(--radius-2);
      padding: var(--space-3) var(--space-4);
      box-shadow: var(--shadow-1);
      transition: var(--transition-1);
      display: flex;
      flex-direction: column;
      gap: var(--space-1);
    }
    .feature-block:hover {
      transform: translateY(-3px);
      border-color: rgba(0,229,255,0.28);
      box-shadow: var(--shadow-2);
    }
    .feature-block h3 { color: var(--color-4); font-size: 1.05rem; }
    .feature-block p { color: var(--color-7); font-size: 0.95rem; margin: 0; }

    /* timeline */
    .steps-list { list-style: none; padding: 0; counter-reset: step; }
    .timeline-item {
      counter-increment: step;
      display: flex;
      gap: var(--space-3);
      align-items: flex-start;
      margin-bottom: var(--space-4);
      position: relative;
    }
    .timeline-item::before {
      content: counter(step);
      display: flex;
      align-items: center;
      justify-content: center;
      width: 48px;
      height: 48px;
      min-width: 48px;
      background: linear-gradient(135deg, var(--color-4), var(--color-5));
      color: var(--color-1);
      font-weight: 800;
      font-size: 1.1rem;
      border-radius: 50%;
      box-shadow: 0 0 16px rgba(0,229,255,0.4);
      margin-top: 2px;
    }
    .timeline-content h3 { color: var(--color-6); font-size: 1.1rem; margin-bottom: 0.4rem; }
    .timeline-content p { color: var(--color-7); margin: 0; }

    /* DL */
    dl.feature-list dt {
      color: var(--color-4);
      font-weight: 700;
      margin-top: var(--space-2);
      margin-bottom: 0.25rem;
    }
    dl.feature-list dd {
      color: var(--color-7);
      margin-left: var(--space-3);
      margin-bottom: var(--space-1);
    }

    /* grids */
    .cards-grid-2 {
      display: grid;
      grid-template-columns: 1fr;
      gap: var(--space-3);
      margin: var(--space-3) 0;
    }
    .cards-grid-3 {
      display: grid;
      grid-template-columns: 1fr;
      gap: var(--space-3);
      margin: var(--space-3) 0;
    }
    .feature-list-grid {
      display: grid;
      grid-template-columns: 1fr;
      gap: var(--space-3);
    }

    /* aside info-card */
    aside.info-card {
      background: linear-gradient(135deg, rgba(0,229,255,0.08) 0%, var(--color-2) 100%);
      border-left: 4px solid var(--color-4);
      border-radius: 0 var(--radius-1) var(--radius-1) 0;
      padding: var(--space-3) var(--space-4);
      margin-top: var(--space-3);
    }
    aside.info-card p { color: var(--color-7); margin: 0; }

    /* === LAYOUT STYLES === */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(10, 14, 26, 0.97);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,229,255,0.12);
      box-shadow: 0 2px 24px rgba(0,0,0,0.5);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: var(--space-2);
      padding-top: 0.85rem;
      padding-bottom: 0.85rem;
      flex-wrap: wrap;
    }
    .logo {
      display: flex;
      align-items: center;
      flex-shrink: 0;
      z-index: 10;
    }
    .logo-text {
      font-size: 1.35rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--color-4), var(--color-5));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.01em;
    }

    .hamburger {
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 5px;
      width: 44px;
      height: 44px;
      background: rgba(0,229,255,0.07);
      border: 1px solid rgba(0,229,255,0.2);
      border-radius: var(--radius-1);
      cursor: pointer;
      padding: 0;
      transition: var(--transition-1);
      z-index: 10;
    }
    .hamburger:hover { background: rgba(0,229,255,0.15); }
    .hamburger span {
      display: block;
      width: 22px;
      height: 2px;
      background: var(--color-4);
      border-radius: 2px;
      transition: var(--transition-1);
    }
    .hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
    .hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
    .hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

    header nav { display: flex; align-items: center; }
    .nav-list {
      list-style: none;
      padding: 0;
      margin: 0;
      display: flex;
      gap: var(--space-2);
      align-items: center;
    }
    .nav-list a {
      color: var(--color-7);
      font-weight: 600;
      font-size: 0.95rem;
      padding: 0.4rem 0.75rem;
      border-radius: var(--radius-1);
      transition: var(--transition-1);
      white-space: nowrap;
    }
    .nav-list a:hover { color: var(--color-4); background: rgba(0,229,255,0.08); }

    .cta-button {
      font-size: 0.9rem;
      padding: 0.6rem 1.4rem;
      max-width: 200px;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    .site-footer {
      background: var(--color-10);
      border-top: 1px solid rgba(0,229,255,0.1);
      padding: var(--space-5) 0 var(--space-4);
    }
    .footer-inner {
      display: flex;
      flex-direction: column;
      gap: var(--space-3);
      align-items: center;
      text-align: center;
    }
    .footer-nav-list {
      list-style: none;
      padding: 0;
      margin: 0;
      display: flex;
      flex-wrap: wrap;
      gap: var(--space-2) var(--space-3);
      justify-content: center;
    }
    .footer-nav-list a {
      color: var(--color-7);
      font-size: 0.9rem;
      transition: color 0.2s;
    }
    .footer-nav-list a:hover { color: var(--color-4); }
    .footer-disclaimer {
      color: rgba(176,196,216,0.55);
      font-size: 0.82rem;
      line-height: 1.6;
      max-width: 600px;
      margin: 0 auto;
    }

    @media (max-width: 767px) {
      .hamburger { display: flex; }
      header nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10,14,26,0.99);
        border-bottom: 1px solid rgba(0,229,255,0.12);
        padding: var(--space-3);
        box-shadow: 0 8px 32px rgba(0,0,0,0.4);
      }
      header nav.open { display: flex; }
      .nav-list { flex-direction: column; width: 100%; gap: var(--space-1); }
      .nav-list a { display: block; padding: 0.7rem 1rem; }
      .header-inner { flex-wrap: wrap; row-gap: var(--space-1); }
      .cta-button {
        width: 100%;
        max-width: 100%;
        text-align: center;
        order: 10;
        flex-basis: 100%;
      }
    }
    @media (min-width: 768px) {
      .hamburger { display: none; }
      header nav { display: flex !important; }
    }

@media (max-width: 767px) {
      .hamburger { display: flex; }
      header nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10,14,26,0.99);
        border-bottom: 1px solid rgba(0,229,255,0.12);
        padding: var(--space-3);
        box-shadow: 0 8px 32px rgba(0,0,0,0.4);
      }
      header nav.open { display: flex; }
      .nav-list { flex-direction: column; width: 100%; gap: var(--space-1); }
      .nav-list a { display: block; padding: 0.7rem 1rem; }
      .header-inner { flex-wrap: wrap; row-gap: var(--space-1); }
      .cta-button {
        width: 100%;
        max-width: 100%;
        text-align: center;
        order: 10;
        flex-basis: 100%;
      }
    }

@media (min-width: 768px) {
      .hamburger { display: none; }
      header nav { display: flex !important; }
    }