:root {
      --bg-top: #0b1720;
      --bg-bottom: #0f1f25;
      --panel: rgba(255, 255, 255, 0.08);
      --panel-strong: rgba(255, 255, 255, 0.12);
      --border: rgba(255, 255, 255, 0.12);
      --text: #ffffff;
      --muted: rgba(255, 255, 255, 0.72);
      --soft: rgba(255, 255, 255, 0.54);
      --cyan: #4bc1d9;
      --teal: #00a99d;
      --ink: #13313a;
      --slate: #49656d;
      --mist: #eef8fa;
      --shadow: 0 25px 80px rgba(19, 49, 58, 0.18);
      --radius-xl: 32px;
      --radius-lg: 28px;
      --radius-md: 22px;
    }

    * {
      box-sizing: border-box;
    }

    [hidden] {
      display: none !important;
    }

    body {
      margin: 0;
      font-family: "Open Sans",Helvetica,sans-serif;
      color: var(--text);
      background:
        radial-gradient(circle at top left, rgba(75, 193, 217, 0.28), transparent 30%),
        radial-gradient(circle at 80% 20%, rgba(0, 169, 157, 0.20), transparent 24%),
        linear-gradient(180deg, var(--bg-top) 0%, #10252b 45%, var(--bg-bottom) 100%);
      min-height: 100vh;
    }

    .page {
      position: relative;
      max-width: 1280px;
      margin: 0 auto;
      padding: 32px 24px 48px;
    }

    .glow {
      position: absolute;
      border-radius: 999px;
      filter: blur(70px);
      pointer-events: none;
      z-index: 0;
    }

    .glow-left {
      top: 96px;
      left: -80px;
      width: 260px;
      height: 260px;
      background: rgba(75, 193, 217, 0.12);
    }

    .glow-right {
      top: 220px;
      right: 0;
      width: 280px;
      height: 280px;
      background: rgba(0, 169, 157, 0.10);
    }

    .hero,
    .main-grid {
      position: relative;
      z-index: 1;
    }

    .hero {
      display: grid;
      grid-template-columns: 1.25fr 0.75fr;
      border: 1px solid var(--border);
      border-radius: var(--radius-xl);
      overflow: hidden;
      box-shadow: var(--shadow);
      background: rgba(255, 255, 255, 0.05);
      backdrop-filter: blur(14px);
    }

    .hero-left,
    .hero-right {
      padding: 48px;
    }

    .hero-left {
      border-right: 1px solid var(--border);
    }

    .brand-row {
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 40px;
    }

    .brand-mark {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 80px;
      height: 80px;
      border-radius: 24px;
      background: rgba(255, 255, 255, 0.10);
      border: 1px solid var(--border);
      box-shadow: 0 18px 40px rgba(0, 0, 0, 0.18);
    }

    .brand-mark svg {
      width: 44px;
      height: 44px;
      fill: var(--cyan);
    }

    .brand-label {
      margin: 0 0 6px;
      color: rgba(75, 193, 217, 0.92);
      font-size: 1.1rem;
      font-weight: 400;
      /* letter-spacing: 0.24em; */
    }

    .brand-subtitle {
      margin: 0;
      color: var(--soft);
      font-size: 0.95rem;
    }

    .pill {
      display: inline-flex;
      align-items: center;
      padding: 10px 16px;
      border-radius: 999px;
      border: 1px solid rgba(75, 193, 217, 0.25);
      background: rgba(75, 193, 217, 0.10);
      color: var(--cyan);
      font-size: 0.95rem;
      font-weight: 400;
    }

    h1 {
      /* max-width: 12ch; */
      margin: 24px 0 0;
      font-size: clamp(2.6rem, 5vw, 4.3rem);
      line-height: 1.04;
      font-weight: 300;
      /* letter-spacing: 0.5em; */
    }

    .lead {
      max-width: 720px;
      margin: 24px 0 0;
      color: var(--muted);
      font-size: 1.1rem;
      line-height: 1.9;
    }

    .chip-row {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      margin-top: 32px;
    }

    .chip {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 14px 16px;
      border-radius: 18px;
      border: 1px solid var(--border);
      background: rgba(255, 255, 255, 0.05);
      color: var(--muted);
      font-size: 0.95rem;
    }

    .chip i {
      color: var(--cyan);
      font-size: 0.95rem;
    }

    .hero-right {
      position: relative;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      gap: 24px;
    }

    .floating-orb,
    .floating-orb-2 {
      position: absolute;
      border-radius: 999px;
      pointer-events: none;
    }

    .floating-orb {
      top: 32px;
      right: 32px;
      width: 110px;
      height: 110px;
      background: rgba(75, 193, 217, 0.10);
      border: 1px solid rgba(75, 193, 217, 0.16);
    }

    .floating-orb-2 {
      bottom: 24px;
      right: 56px;
      width: 160px;
      height: 160px;
      background: rgba(0, 169, 157, 0.08);
      filter: blur(18px);
    }

    .download-card {
      position: relative;
      z-index: 1;
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
      background: rgba(255, 255, 255, 0.10);
      padding: 28px;
      box-shadow: 0 20px 45px rgba(0, 0, 0, 0.16);
      backdrop-filter: blur(10px);
    }

    .section-label {
      margin: 0;
      color: var(--cyan);
      font-size: 0.82rem;
      font-weight: 700;
      letter-spacing: 0.28em;
      text-transform: uppercase;
    }

    .download-card h2 {
      margin: 12px 0 0;
      font-size: 2rem;
      line-height: 1.1;
      font-weight: 300;
    }

    .download-card p {
      margin: 18px 0 0;
      color: var(--muted);
      line-height: 1.8;
      font-size: 0.98rem;
    }

    .download-button {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      width: 100%;
      margin-top: 28px;
      padding: 18px 22px;
      border-radius: 18px;
      background: linear-gradient(90deg, var(--cyan), var(--teal));
      color: #0b1720;
      text-decoration: none;
      text-align: center;
      font-weight: 700;
      box-shadow: 0 20px 40px rgba(0, 169, 157, 0.24);
      transition: transform 0.2s ease, filter 0.2s ease;
    }

    .download-button:hover,
    .download-button:focus {
      transform: translateY(-2px);
      filter: brightness(1.04);
    }

    .download-button-secondary {
      margin-bottom: 20px;
      background: rgba(255, 255, 255, 0.08);
      color: var(--text);
      border: 1px solid rgba(255, 255, 255, 0.14);
      box-shadow: none;
    }

    .download-button-secondary:hover,
    .download-button-secondary:focus {
      filter: none;
      background: rgba(255, 255, 255, 0.12);
    }

    .tiny-note {
      margin-top: 14px;
      color: var(--soft);
      font-size: 0.8rem;
      line-height: 1.7;
    }

    .need-grid {
      position: relative;
      z-index: 1;
      display: grid;
      gap: 14px;
      grid-template-columns: 1fr;
    }

    .fast-lane {
      margin-top: 20px;
      display: grid;
      gap: 14px;
      grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .fast-card {
      border: 1px solid var(--border);
      border-radius: 20px;
      background: rgba(255, 255, 255, 0.06);
      padding: 18px 16px;
    }

    .fast-step {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 34px;
      height: 34px;
      border-radius: 999px;
      background: rgba(75, 193, 217, 0.18);
      color: var(--cyan);
      font-weight: 700;
      margin-bottom: 12px;
    }

    .fast-title {
      margin: 0 0 8px;
      font-size: 1.05rem;
      font-weight: 700;
    }

    .fast-icon {
      margin: 0 0 10px;
      color: var(--cyan);
      font-size: 1rem;
    }

    .fast-copy {
      margin: 0;
      color: var(--muted);
      line-height: 1.6;
      font-size: 0.96rem;
    }

    .need-card {
      border: 1px solid var(--border);
      border-radius: 20px;
      background: rgba(255, 255, 255, 0.05);
      padding: 16px;
    }

    .need-icon {
      margin-bottom: 10px;
      color: var(--cyan);
      font-size: 1rem;
    }

    .need-label {
      margin: 0;
      color: var(--soft);
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.24em;
      text-transform: uppercase;
    }

    .need-value {
      margin: 10px 0 0;
      font-size: 0.95rem;
      font-weight: 700;
    }

    .main-grid {
      display: grid;
      grid-template-columns: 1.05fr 0.95fr;
      gap: 24px;
      margin-top: 28px;
    }

    .os-switcher,
    .platform-card {
      position: relative;
      z-index: 1;
      margin-top: 28px;
      border: 1px solid var(--border);
      border-radius: var(--radius-xl);
      background: rgba(255, 255, 255, 0.05);
      box-shadow: var(--shadow);
      backdrop-filter: blur(14px);
    }

    .os-switcher {
      padding: 28px 32px 32px;
    }

    .os-switcher-copy h2,
    .platform-card-head h3 {
      margin: 8px 0 0;
      font-size: 2rem;
      line-height: 1.1;
      font-weight: 300;
    }

    .os-switcher-copy p:last-child,
    .platform-card-head p:last-child {
      margin: 14px 0 0;
      color: var(--muted);
      line-height: 1.75;
    }

    .os-switcher-controls {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 16px;
      margin-top: 24px;
    }

    .os-tab {
      display: block;
      width: 100%;
      padding: 18px 18px 20px;
      border-radius: 22px;
      border: 1px solid rgba(255, 255, 255, 0.12);
      background: rgba(255, 255, 255, 0.05);
      color: var(--text);
      text-align: left;
      cursor: pointer;
      transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
    }

    .os-tab:hover,
    .os-tab:focus-visible {
      transform: translateY(-2px);
      border-color: rgba(75, 193, 217, 0.34);
      background: rgba(75, 193, 217, 0.09);
      outline: none;
    }

    .os-tab.is-active {
      border-color: rgba(75, 193, 217, 0.42);
      background: linear-gradient(135deg, rgba(75, 193, 217, 0.18), rgba(0, 169, 157, 0.16));
      box-shadow: 0 18px 36px rgba(0, 0, 0, 0.18);
    }

    .os-tab-name {
      display: block;
      font-size: 1.1rem;
      font-weight: 700;
    }

    .os-tab-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 34px;
      height: 34px;
      margin-bottom: 12px;
      border-radius: 999px;
      background: rgba(75, 193, 217, 0.14);
      color: var(--cyan);
      font-size: 1rem;
    }

    .os-tab-copy {
      display: block;
      margin-top: 8px;
      color: var(--muted);
      line-height: 1.5;
      font-size: 0.94rem;
    }

    .os-detected-banner {
      margin-top: 18px;
      padding: 14px 16px;
      border-radius: 18px;
      border: 1px solid rgba(75, 193, 217, 0.18);
      background: rgba(75, 193, 217, 0.10);
      color: var(--mist);
      line-height: 1.65;
    }

    .os-panel {
      position: relative;
      z-index: 1;
    }

    .section-label-teal {
      color: var(--teal);
    }

    .section-label-cyan {
      color: var(--cyan);
    }

    .white-card,
    .glass-card,
    .notice-card,
    .footer {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow);
    }

    .white-card {
      border: 1px solid #dde7ea;
      background: #ffffff;
      color: var(--ink);
      overflow: hidden;
    }

    .white-card-header {
      padding: 24px 32px;
      border-bottom: 1px solid #e3edf0;
    }

    .white-card-header h3 {
      margin: 8px 0 0;
      font-size: 1.9rem;
      line-height: 1.15;
      font-weight:300;
    }

    .white-card-body {
      padding: 28px 32px 32px;
    }

    .steps {
      list-style: none;
      margin: 0;
      padding: 0;
      display: grid;
      gap: 18px;
    }

    .step {
      display: flex;
      gap: 16px;
      align-items: flex-start;
    }

    .step-number {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      flex: 0 0 40px;
      border-radius: 16px;
      background: var(--mist);
      color: var(--ink);
      font-weight: 700;
    }

    .step-title {
      margin: 0;
      font-size: 1rem;
      font-weight: 700;
    }

    .step-copy {
      margin: 6px 0 0;
      color: var(--slate);
      line-height: 1.8;
    }

    .side-stack {
      display: grid;
      gap: 24px;
    }

    .glass-card {
      border: 1px solid var(--border);
      background: rgba(255, 255, 255, 0.05);
      padding: 28px;
      backdrop-filter: blur(10px);
    }

    .need-list {
      list-style: none;
      margin: 20px 0 0;
      padding: 0;
      display: grid;
      gap: 14px;
    }

    .need-list li {
      padding: 14px 16px;
      border-radius: 18px;
      border: 1px solid var(--border);
      background: rgba(255, 255, 255, 0.05);
      color: var(--muted);
      line-height: 1.7;
    }

    .notice-card {
      border: 1px solid rgba(75, 193, 217, 0.22);
      background: linear-gradient(135deg, rgba(75, 193, 217, 0.12), rgba(0, 169, 157, 0.12));
      padding: 28px;
      backdrop-filter: blur(10px);
    }

    .notice-card p {
      margin: 18px 0 0;
      color: rgba(255, 255, 255, 0.82);
      line-height: 1.9;
    }

    .footer {
      display: flex;
      justify-content: space-between;
      gap: 16px;
      margin-top: 28px;
      padding: 18px 24px;
      border: 1px solid var(--border);
      background: rgba(255, 255, 255, 0.05);
      color: var(--soft);
      font-size: 0.95rem;
    }

    .windows-guide {
      margin-top: 28px;
      position: relative;
      z-index: 1;
      border: 1px solid var(--border);
      border-radius: var(--radius-xl);
      overflow: hidden;
      box-shadow: var(--shadow);
      background: rgba(255, 255, 255, 0.05);
      backdrop-filter: blur(14px);
    }

    .guide-head {
      padding: 28px 32px 18px;
      border-bottom: 1px solid var(--border);
    }

    .guide-head h3 {
      margin: 6px 0 0;
      font-size: 2rem;
      line-height: 1.1;
      font-weight:300;
    }

    .guide-head p {
      margin: 12px 0 0;
      color: var(--muted);
      max-width: 760px;
      line-height: 1.7;
    }

    .guide-grid {
      display: grid;
      grid-template-columns: 0.9fr 1.1fr;
    }

    .guide-copy,
    .guide-shots {
      padding: 28px 32px 32px;
    }

    .guide-copy {
      border-right: 1px solid var(--border);
    }

    .mini-steps {
      display: grid;
      gap: 14px;
    }

    .mini-step {
      display: grid;
      grid-template-columns: 42px 1fr;
      gap: 12px;
      align-items: start;
      padding: 14px 14px 14px 12px;
      border-radius: 18px;
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.08);
    }

    .mini-step-number {
      width: 42px;
      height: 42px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 14px;
      background: rgba(75, 193, 217, 0.16);
      color: var(--cyan);
      font-weight: 700;
      font-size: 1rem;
    }

    .mini-step-title {
      margin: 0 0 4px;
      font-size: 1rem;
      font-weight: 700;
      color: var(--text);
    }

    .mini-step-copy {
      margin: 0;
      color: var(--muted);
      line-height: 1.6;
    }

    .helper-note {
      margin-top: 18px;
      padding: 14px 16px;
      border-radius: 18px;
      background: rgba(0, 169, 157, 0.12);
      border: 1px solid rgba(0, 169, 157, 0.18);
      color: var(--mist);
      line-height: 1.65;
    }

    .shots-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 18px;
    }

    .shot-card {
      border-radius: 22px;
      overflow: hidden;
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.08);
    }

    .shot-card img {
      display: block;
      width: 100%;
      height: auto;
      background: #ffffff;
    }

    .shot-card figcaption {
      padding: 14px 16px 16px;
      color: var(--muted);
      line-height: 1.5;
      font-size: 0.95rem;
    }

    .linux-shots {
      margin-top: 18px;
    }

    .platform-card {
      overflow: hidden;
    }

    .platform-card-head {
      display: flex;
      justify-content: space-between;
      gap: 18px;
      align-items: start;
      padding: 28px 32px 20px;
      border-bottom: 1px solid var(--border);
    }

    .platform-chip {
      display: inline-flex;
      align-items: center;
      padding: 10px 14px;
      border-radius: 999px;
      border: 1px solid rgba(75, 193, 217, 0.22);
      background: rgba(75, 193, 217, 0.10);
      color: var(--cyan);
      font-size: 0.88rem;
      font-weight: 700;
      white-space: nowrap;
    }

    .platform-grid {
      display: grid;
      grid-template-columns: 1fr 0.9fr;
    }

    .platform-column {
      padding: 28px 32px 32px;
    }

    .platform-column:first-child {
      border-right: 1px solid var(--border);
    }

    .visual-checklist {
      display: grid;
      gap: 14px;
    }

    .visual-check {
      display: flex;
      justify-content: space-between;
      gap: 16px;
      padding: 16px 18px;
      border-radius: 18px;
      border: 1px solid rgba(255, 255, 255, 0.08);
      background: rgba(255, 255, 255, 0.05);
      color: var(--mist);
    }

    .visual-check strong {
      text-align: right;
    }

    .visual-check-label {
      color: var(--soft);
      font-size: 0.85rem;
      font-weight: 700;
      letter-spacing: 0.1em;
      text-transform: uppercase;
    }

    strong {
      color: inherit;
    }

    @media (max-width: 1080px) {
      .hero,
      .main-grid,
      .guide-grid,
      .platform-grid {
        grid-template-columns: 1fr;
      }

      .hero-left {
        border-right: 0;
        border-bottom: 1px solid var(--border);
      }

      .guide-copy {
        border-right: 0;
        border-bottom: 1px solid var(--border);
      }

      .platform-column:first-child {
        border-right: 0;
        border-bottom: 1px solid var(--border);
      }
    }

    @media (max-width: 720px) {
      .page {
        padding: 18px 14px 28px;
      }

      .hero-left,
      .hero-right,
      .white-card-header,
      .white-card-body,
      .glass-card,
      .notice-card,
      .os-switcher,
      .platform-card-head,
      .platform-column {
        padding-left: 20px;
        padding-right: 20px;
      }

      .hero-left,
      .hero-right {
        padding-top: 28px;
        padding-bottom: 28px;
      }

      .brand-row {
        align-items: flex-start;
      }

      .need-grid {
        grid-template-columns: 1fr;
      }

      .fast-lane,
      .shots-grid,
      .os-switcher-controls {
        grid-template-columns: 1fr;
      }

      .platform-card-head,
      .visual-check {
        flex-direction: column;
      }

      .platform-chip,
      .visual-check strong {
        white-space: normal;
        text-align: left;
      }

      .footer {
        flex-direction: column;
      }
    }