/* Stylesheet for frontend/zh-CN/tutorial.html */
    :root {
      --bg: #f7f5f2;
      --bg-card: #ffffff;
      --bg-soft: #eef6f4;
      --ink: #16202e;
      --ink-soft: #5c6b7a;
      --accent: #2d9c8a;
      --accent-light: #d4f0eb;
      --accent-dark: #1f7a6c;
      --warm: #e8a87c;
      --warm-light: #fdf0e8;
      --line: #e2e6ea;
      --shadow: 0 4px 24px rgba(22, 32, 46, 0.06);
      --shadow-lg: 0 24px 64px rgba(22, 32, 46, 0.12);
      --font-display: 'Outfit', 'Noto Sans SC', sans-serif;
      --font-body: 'Noto Sans SC', sans-serif;
    }

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

    html { scroll-behavior: smooth; }

    body {
      font-family: var(--font-body);
      background: var(--bg);
      color: var(--ink);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    body.menu-open {
      overflow: hidden;
      height: 100vh;
    }

    a { color: inherit; text-decoration: none; }

    .container {
      width: min(1180px, 92vw);
      margin: 0 auto;
    }

    .reveal {
      opacity: 0;
      transform: translateY(32px);
      transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
    }

    .reveal.visible {
      opacity: 1;
      transform: translateY(0);
    }

    /* Floating pill nav (shared) */
    .nav-wrap {
      position: fixed;
      top: 20px;
      left: 0;
      right: 0;
      z-index: 100;
      display: flex;
      justify-content: center;
      padding: 0 4vw;
      pointer-events: none;
    }

    .nav-pill {
      pointer-events: auto;
      display: flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.78);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid rgba(255, 255, 255, 0.9);
      box-shadow: 0 8px 32px rgba(22, 32, 46, 0.1);
      border-radius: 999px;
      padding: 8px 10px 8px 18px;
      width: min(880px, 100%);
      justify-content: space-between;
      transition: box-shadow 0.3s;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 1.2rem;
      letter-spacing: -0.02em;
      flex-shrink: 0;
    }

    .logo-mark {
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }

    .logo-mark img {
      width: 100%;
      height: 100%;
      object-fit: contain;
      display: block;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 4px;
      list-style: none;
    }

    .nav-links a {
      font-size: 0.88rem;
      font-weight: 500;
      color: var(--ink-soft);
      padding: 8px 16px;
      border-radius: 999px;
      transition: all 0.2s;
    }

    .nav-links a:hover {
      color: var(--accent-dark);
      background: var(--accent-light);
    }

    .nav-links a.active {
      color: #fff;
      background: var(--ink);
    }

    .nav-right {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .lang-chip {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 0.8rem;
      color: var(--ink-soft);
      padding: 8px 14px;
      border-radius: 999px;
      border: 1px solid var(--line);
      cursor: pointer;
      background: #fff;
    }

    .lang-chip i { color: var(--accent); }

.lang-switch { position: relative; }

.lang-chip { cursor: pointer; border: none; font-family: inherit; transition: border-color 0.2s, color 0.2s; }
.lang-chip:hover { border-color: var(--accent); color: var(--accent-dark); }

.lang-caret { font-size: 0.6rem; margin-left: 2px; color: var(--ink-soft); transition: transform 0.2s; }
.lang-switch.open .lang-caret { transform: rotate(180deg); }

.lang-dropdown {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 200px;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 8px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.2s, transform 0.2s, visibility 0.2s;
  z-index: 120;
}

.lang-switch.open .lang-dropdown { opacity: 1; visibility: visible; transform: translateY(0); }

.lang-option {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: none;
  background: none;
  font-family: var(--font-body);
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  transition: background 0.15s;
  text-align: left;
}

.lang-option:hover:not(:disabled) { background: var(--accent-light); }
.lang-option:disabled { color: var(--ink-soft); cursor: not-allowed; opacity: 0.7; }

.lang-flag { font-size: 1rem; line-height: 1; flex-shrink: 0; }
.lang-option-name { flex: 1; }
.lang-check { color: var(--accent); font-size: 0.8rem; flex-shrink: 0; }

.lang-soon {
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-soft);
  background: var(--bg);
  border: 1px solid var(--line);
  padding: 2px 8px;
  border-radius: 999px;
  flex-shrink: 0;
  white-space: nowrap;
}


    .nav-gh {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--ink);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1rem;
      transition: transform 0.2s, background 0.2s;
    }

    .nav-gh:hover {
      transform: rotate(-8deg) scale(1.08);
      background: var(--accent-dark);
    }

    .menu-toggle {
      display: none;
      align-items: center;
      justify-content: center;
      width: 36px;
      height: 36px;
      flex-shrink: 0;
      background: none;
      border: none;
      font-size: 1.1rem;
      color: var(--ink);
      cursor: pointer;
      padding: 0;
    }

    .mobile-menu { display: none; }


    @media (max-width: 1020px) {
      .nav-links { display: none; }
      .menu-toggle { display: flex; }

      .mobile-menu.open {
        display: flex;
        position: fixed;
        top: 86px;
        left: 4vw;
        right: 4vw;
        z-index: 99;
        flex-direction: column;
        gap: 4px;
        background: rgba(255, 255, 255, 0.96);
        backdrop-filter: blur(16px);
        border: 1px solid var(--line);
        border-radius: 20px;
        padding: 14px;
        box-shadow: var(--shadow-lg);
        list-style: none;
      }

      .mobile-menu a {
        display: block;
        padding: 12px 18px;
        border-radius: 12px;
        font-weight: 500;
        color: var(--ink);
      }

      .mobile-menu a:hover {
        background: var(--accent-light);
        color: var(--accent-dark);
      }
    }

    /* Buttons (shared) */
    .btn-major {
      display: inline-flex;
      align-items: center;
      gap: 12px;
      padding: 16px 32px;
      border-radius: 999px;
      background: var(--ink);
      color: #fff;
      font-size: 0.98rem;
      font-weight: 600;
      transition: all 0.25s;
      position: relative;
      overflow: hidden;
      border: none;
      cursor: pointer;
    }

    .btn-major .arr {
      width: 26px;
      height: 26px;
      border-radius: 50%;
      background: var(--accent);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 0.7rem;
      transition: transform 0.25s;
    }

    .btn-major:hover {
      background: var(--accent-dark);
      transform: translateY(-3px);
      box-shadow: 0 12px 28px rgba(31, 122, 108, 0.35);
    }

    .btn-major:hover .arr {
      transform: translateX(3px);
      background: rgba(255, 255, 255, 0.22);
    }

    .btn-ghost {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 15px 28px;
      border-radius: 999px;
      border: 1.5px solid var(--ink);
      color: var(--ink);
      font-size: 0.95rem;
      font-weight: 600;
      transition: all 0.25s;
      background: transparent;
    }

    .btn-ghost:hover {
      background: var(--ink);
      color: #fff;
      transform: translateY(-3px);
    }

    .btn-small {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 20px;
      border-radius: 999px;
      border: 1.5px solid var(--line);
      color: var(--ink);
      font-size: 0.85rem;
      font-weight: 600;
      transition: all 0.2s;
    }

    .btn-small:hover {
      border-color: var(--accent);
      background: var(--accent-light);
      color: var(--accent-dark);
    }

    /* Section head shared */
    section { padding: 96px 0; }

    .sec-head {
      display: flex;
      align-items: baseline;
      justify-content: space-between;
      gap: 24px;
      margin-bottom: 56px;
      flex-wrap: wrap;
    }

    .sec-head .kicker {
      font-size: 0.82rem;
      font-weight: 600;
      letter-spacing: 0.22em;
      color: var(--accent-dark);
      display: block;
      margin-bottom: 14px;
    }

    .sec-head h2 {
      font-family: var(--font-display);
      font-size: clamp(1.9rem, 4vw, 2.8rem);
      font-weight: 700;
      letter-spacing: -0.03em;
      line-height: 1.15;
    }

    .sec-head .side-note {
      max-width: 360px;
      font-size: 0.95rem;
      color: var(--ink-soft);
      line-height: 1.8;
    }

    /* Tutorial hero */
    .tut-hero {
      position: relative;
      padding: 148px 0 72px;
      overflow: hidden;
    }

    .tut-hero-orb {
      position: absolute;
      top: -140px;
      left: -100px;
      width: 480px;
      height: 480px;
      border-radius: 50%;
      background: var(--accent-light);
      filter: blur(80px);
      opacity: 0.55;
      pointer-events: none;
    }

    .tut-hero-inner {
      position: relative;
      z-index: 1;
      text-align: center;
    }

    .tut-hero .hero-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      font-size: 0.85rem;
      font-weight: 600;
      letter-spacing: 0.2em;
      color: var(--accent-dark);
      margin-bottom: 24px;
    }

    .tut-hero .hero-eyebrow .dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--accent);
    }

    .tut-hero h1 {
      font-family: var(--font-display);
      font-size: clamp(2.4rem, 5.5vw, 4rem);
      font-weight: 800;
      line-height: 1.12;
      letter-spacing: -0.03em;
      margin: 0 auto 22px;
      max-width: 16em;
    }

    .tut-hero h1 .accent-word {
      background: linear-gradient(120deg, var(--accent) 0%, #3db89e 60%, var(--warm) 110%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .tut-hero p.lead {
      max-width: 560px;
      margin: 0 auto 40px;
      font-size: 1.05rem;
      color: var(--ink-soft);
      line-height: 1.85;
    }

    .tut-hero p.lead strong { color: var(--ink); }

    .quick-jump {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
      margin-bottom: 40px;
    }

    .quick-jump a {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 11px 22px;
      border-radius: 999px;
      border: 1.5px solid var(--line);
      background: var(--bg-card);
      font-size: 0.9rem;
      font-weight: 600;
      color: var(--ink);
      transition: all 0.2s;
    }

    .quick-jump a:hover {
      border-color: var(--accent);
      color: var(--accent-dark);
      transform: translateY(-2px);
    }

    .time-row {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 28px;
    }

    .time-row .t-item {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.85rem;
      color: var(--ink-soft);
    }

    .time-row .t-item i { color: var(--accent); }

    /* Step grid — five action cards */
    .steps-section { background: var(--bg-card); border-top: 1px solid var(--line); }

    .tut-timeline {
      display: grid;
      grid-template-columns: repeat(5, minmax(0, 1fr));
      gap: 16px;
      position: relative;
    }

    .tut-step {
      position: relative;
      display: flex;
      flex-direction: column;
      height: 100%;
    }

    .tut-step .step-num {
      position: absolute;
      top: -14px;
      left: 20px;
      z-index: 2;
      width: 36px;
      height: 36px;
      border-radius: 12px;
      background: var(--ink);
      color: #fff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: var(--font-display);
      font-size: 0.95rem;
      font-weight: 800;
      box-shadow: 0 8px 20px rgba(22, 32, 46, 0.18);
    }

    .tut-step:hover .step-num {
      background: var(--accent-dark);
    }

    .step-body {
      flex: 1;
      display: flex;
      flex-direction: column;
      background: var(--bg);
      border: 1px solid var(--line);
      border-radius: 20px;
      padding: 36px 20px 22px;
      transition: border-color 0.25s, box-shadow 0.25s, transform 0.25s;
    }

    .tut-step:hover .step-body {
      border-color: var(--accent);
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
    }

    .step-body .step-icon {
      width: 44px;
      height: 44px;
      border-radius: 14px;
      background: var(--accent-light);
      color: var(--accent-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.05rem;
      margin-bottom: 16px;
    }

    .step-body h3 {
      font-family: var(--font-display);
      font-size: 1.02rem;
      font-weight: 700;
      line-height: 1.35;
      margin-bottom: 10px;
      letter-spacing: -0.02em;
    }

    .step-body p {
      font-size: 0.84rem;
      color: var(--ink-soft);
      line-height: 1.7;
      flex: 1;
    }

    .step-tip {
      display: flex;
      align-items: flex-start;
      gap: 8px;
      margin-top: 16px;
      padding: 10px 12px;
      background: var(--bg-card);
      border: 1px dashed var(--line);
      border-radius: 12px;
      font-size: 0.76rem;
      color: var(--accent-dark);
      line-height: 1.55;
    }

    .step-tip i { margin-top: 2px; flex-shrink: 0; font-size: 0.72rem; }

    /* Inline code chips */
    code, .kbd {
      display: inline;
      font-family: 'Outfit', ui-monospace, monospace;
      font-size: 0.84em;
      font-weight: 600;
      color: var(--accent-dark);
      background: var(--accent-light);
      padding: 1px 7px;
      border-radius: 6px;
      white-space: nowrap;
    }

    /* OS tabs + editorial panel */
    .os-tabs {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 10px;
      margin-bottom: 36px;
    }

    .os-tab {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 12px 24px;
      border-radius: 999px;
      border: 1.5px solid var(--line);
      background: var(--bg-card);
      font-size: 0.92rem;
      font-weight: 600;
      color: var(--ink-soft);
      cursor: pointer;
      transition: all 0.22s;
      font-family: var(--font-body);
    }

    .os-tab i { font-size: 1.05rem; }

    .os-tab:hover {
      border-color: var(--accent);
      color: var(--accent-dark);
    }

    .os-tab.active {
      background: var(--ink);
      border-color: var(--ink);
      color: #fff;
    }

    .os-panel {
      max-width: 960px;
      margin: 0 auto;
      background: var(--bg-card);
      border: 1px solid var(--line);
      border-radius: 28px;
      box-shadow: var(--shadow-lg);
      padding: 36px 40px 32px;
      display: none;
      overflow: hidden;
      position: relative;
    }

    .os-panel::before {
      content: '';
      position: absolute;
      top: -80px;
      right: -60px;
      width: 220px;
      height: 220px;
      border-radius: 50%;
      background: var(--accent-light);
      opacity: 0.45;
      pointer-events: none;
    }

    .os-panel.active {
      display: block;
      animation: panelin 0.45s cubic-bezier(0.16, 1, 0.3, 1);
    }

    @keyframes panelin {
      from { opacity: 0; transform: translateY(16px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .os-panel-head {
      position: relative;
      z-index: 1;
      display: flex;
      align-items: center;
      gap: 18px;
      margin-bottom: 28px;
    }

    .os-panel .big-icon {
      width: 64px;
      height: 64px;
      border-radius: 18px;
      background: var(--bg);
      border: 1px solid var(--line);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.8rem;
      color: var(--ink);
      flex-shrink: 0;
    }

    .os-panel h3 {
      font-family: var(--font-display);
      font-size: 1.35rem;
      font-weight: 700;
      margin-bottom: 4px;
      letter-spacing: -0.02em;
    }

    .os-panel .os-sub {
      font-size: 0.85rem;
      color: var(--ink-soft);
    }

    /* Step cards inside platform panel — NOT flex-on-li (that breaks inline code) */
    .os-steps {
      list-style: none;
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 14px;
      counter-reset: osstep;
      position: relative;
      z-index: 1;
    }

    .os-steps li {
      display: block;
      background: var(--bg);
      border: 1px solid var(--line);
      border-radius: 16px;
      padding: 18px 18px 18px 52px;
      font-size: 0.9rem;
      color: var(--ink-soft);
      line-height: 1.7;
      counter-increment: osstep;
      position: relative;
      transition: border-color 0.2s, transform 0.2s;
    }

    .os-steps li:hover {
      border-color: var(--accent);
      transform: translateY(-2px);
    }

    .os-steps li::before {
      content: counter(osstep, decimal-leading-zero);
      position: absolute;
      left: 14px;
      top: 18px;
      font-family: var(--font-display);
      font-size: 0.78rem;
      font-weight: 800;
      letter-spacing: 0.04em;
      color: var(--accent-dark);
      background: var(--accent-light);
      width: 28px;
      height: 28px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .os-steps li:last-child:nth-child(odd) {
      grid-column: 1 / -1;
    }

    .os-steps li strong { color: var(--ink); font-weight: 600; }

    /* Linux dual path */
    .path-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
      position: relative;
      z-index: 1;
    }

    .path-card {
      background: var(--bg);
      border: 1px solid var(--line);
      border-radius: 18px;
      padding: 22px 22px 18px;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .path-card.cli {
      background: #1d2836;
      border-color: #1d2836;
      color: #dce4ec;
    }

    .path-label {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.14em;
      color: var(--accent-dark);
      text-transform: uppercase;
    }

    .path-card.cli .path-label { color: #7fd8c4; }

    .path-card h4 {
      font-family: var(--font-display);
      font-size: 1.1rem;
      font-weight: 700;
      color: var(--ink);
      margin-top: -4px;
    }

    .path-card.cli h4 { color: #fff; }

    .path-card p {
      font-size: 0.86rem;
      color: var(--ink-soft);
      line-height: 1.7;
    }

    .path-card.cli p { color: #9aabbc; }

    .path-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .path-list li {
      font-size: 0.86rem;
      color: var(--ink-soft);
      line-height: 1.65;
      padding-left: 18px;
      position: relative;
    }

    .path-list li::before {
      content: '';
      position: absolute;
      left: 0;
      top: 0.55em;
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background: var(--accent);
    }

    .path-card.cli .path-list li { color: #c5d2de; }
    .path-card.cli .path-list li::before { background: #7fd8c4; }
    .path-card.cli code {
      background: rgba(127, 216, 196, 0.15);
      color: #7fd8c4;
    }

    .os-panel-foot {
      margin-top: 24px;
      padding-top: 22px;
      border-top: 1px solid var(--line);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      flex-wrap: wrap;
      position: relative;
      z-index: 1;
    }

    .os-panel-foot p {
      font-size: 0.82rem;
      color: var(--ink-soft);
      max-width: 420px;
    }

    /* Rules section — 2x2 concept cards + code */
    .rules-layout {
      display: grid;
      grid-template-columns: 1.05fr 0.95fr;
      gap: 28px;
      align-items: stretch;
    }

    .rule-points {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
    }

    .rule-point {
      background: var(--bg);
      border: 1px solid var(--line);
      border-radius: 18px;
      padding: 22px 20px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      transition: border-color 0.2s, transform 0.2s;
    }

    .rule-point:hover {
      border-color: var(--accent);
      transform: translateY(-2px);
    }

    .rule-point .r-icon {
      width: 40px;
      height: 40px;
      border-radius: 12px;
      background: var(--accent-light);
      color: var(--accent-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1rem;
      flex-shrink: 0;
    }

    .rule-point h4 {
      font-size: 0.98rem;
      font-weight: 700;
      margin-bottom: 0;
    }

    .rule-point p {
      font-size: 0.84rem;
      color: var(--ink-soft);
      line-height: 1.7;
    }

    .code-peek {
      background: #1d2836;
      border-radius: 20px;
      padding: 28px 26px;
      font-family: 'Outfit', monospace;
      font-size: 0.83rem;
      line-height: 1.9;
      color: #b8c6d4;
      overflow-x: auto;
      box-shadow: var(--shadow-lg);
      height: 100%;
      min-height: 320px;
    }

    .code-peek .c-cmt { color: #5a6b7d; }
    .code-peek .c-key { color: #7fd8c4; }
    .code-peek .c-str { color: #e8b075; }
    .code-peek .c-cmd { color: #e8eef4; }

    .code-peek .code-tab {
      display: flex;
      gap: 16px;
      margin-bottom: 16px;
      padding-bottom: 14px;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    .code-peek .code-tab span {
      font-size: 0.72rem;
      color: #5a6b7d;
      letter-spacing: 0.08em;
    }

    .code-peek .code-tab span.on {
      color: #7fd8c4;
      font-weight: 600;
    }

    /* FAQ (shared) */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      border: 1px solid var(--line);
      border-radius: 16px;
      background: var(--bg-card);
      overflow: hidden;
    }

    .faq-q {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 16px;
      padding: 20px 24px;
      cursor: pointer;
      font-size: 0.98rem;
      font-weight: 600;
    }

    .faq-q i {
      color: var(--accent);
      transition: transform 0.25s;
      flex-shrink: 0;
    }

    .faq-item.open .faq-q i { transform: rotate(45deg); }

    .faq-a {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
    }

    .faq-a p {
      padding: 0 24px 20px;
      font-size: 0.9rem;
      color: var(--ink-soft);
      line-height: 1.8;
    }

    /* CTA band (shared) */
    .cta-band {
      background: linear-gradient(135deg, #1f2a38 0%, #2a3a4d 100%);
      border-radius: 28px;
      padding: 56px 48px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 32px;
      flex-wrap: wrap;
      color: #dce4ec;
    }

    .cta-band h3 {
      font-family: var(--font-display);
      font-size: clamp(1.5rem, 3vw, 2rem);
      font-weight: 700;
      color: #fff;
      margin-bottom: 8px;
    }

    .cta-band p {
      font-size: 0.95rem;
      max-width: 420px;
      line-height: 1.7;
    }

    .cta-band .btn-major {
      background: #fff;
      color: #1f2a38;
    }

    .cta-band .btn-major:hover {
      background: var(--accent-light);
      color: var(--accent-dark);
    }

    .cta-band .btn-major .arr {
      background: var(--accent);
      color: #fff;
    }

    .cta-band .btn-ghost {
      border-color: rgba(255,255,255,0.5);
      color: #fff;
    }

    .cta-band .btn-ghost:hover {
      background: #fff;
      color: #1f2a38;
    }

    .cta-actions {
      display: flex;
      gap: 12px;
      flex-wrap: wrap;
    }

    /* Footer (shared) */
    .footer {
      background: var(--bg-card);
      border-top: 1px solid var(--line);
      padding: 72px 0 0;
      overflow: hidden;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 40px;
      margin-bottom: 56px;
    }

    .footer .logo { margin-bottom: 14px; }

    .footer-desc {
      font-size: 0.88rem;
      line-height: 1.7;
      max-width: 280px;
      color: var(--ink-soft);
    }

    .footer h4 {
      font-size: 0.82rem;
      font-weight: 600;
      letter-spacing: 0.14em;
      color: var(--ink-soft);
      margin-bottom: 18px;
    }

    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 11px;
    }

    .footer-links a {
      font-size: 0.9rem;
      color: var(--ink);
      transition: color 0.2s;
    }

    .footer-links a:hover { color: var(--accent-dark); }

    .footer-lang {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
    }

    .footer-lang a {
      padding: 5px 12px;
      border-radius: 999px;
      font-size: 0.78rem;
      border: 1px solid var(--line);
      color: var(--ink-soft);
      cursor: pointer;
    }

    .footer-lang a.active {
      background: var(--ink);
      border-color: var(--ink);
      color: #fff;
    }

    .footer-bottom {
      border-top: 1px solid var(--line);
      padding: 22px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
      font-size: 0.8rem;
      color: var(--ink-soft);
    }

    .footer-wordmark {
      font-family: var(--font-display);
      font-size: clamp(5rem, 16vw, 13rem);
      font-weight: 800;
      letter-spacing: -0.04em;
      line-height: 0.9;
      text-align: center;
      color: transparent;
      -webkit-text-stroke: 1.5px var(--line);
      user-select: none;
      margin-bottom: -0.18em;
      pointer-events: none;
    }

    /* Responsive */
    @media (max-width: 1100px) {
      .tut-timeline {
        grid-template-columns: repeat(3, minmax(0, 1fr));
      }
    }

    @media (max-width: 900px) {
      .tut-timeline {
        grid-template-columns: 1fr 1fr;
      }

      .rules-layout {
        grid-template-columns: 1fr;
        gap: 20px;
      }

      .os-steps {
        grid-template-columns: 1fr;
      }

      .os-steps li:last-child:nth-child(odd) {
        grid-column: auto;
      }

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

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

      .cta-band {
        flex-direction: column;
        text-align: center;
      }

      .cta-band p { margin: 0 auto; }

      .cta-actions { justify-content: center; }

      .os-panel { padding: 28px 22px 24px; }
    }

    @media (max-width: 560px) {
      .lang-chip-text,
      .lang-caret {
        display: none;
      }

      .lang-chip {
        width: 36px;
        height: 36px;
        padding: 0;
        justify-content: center;
        border-radius: 50%;
        background: var(--ink);
        border-color: var(--ink);
      }

      .lang-chip i {
        color: #fff;
      }

      .lang-dropdown {
        right: -8px;
      }
      .footer-grid { grid-template-columns: 1fr; }
      section { padding: 64px 0; }
      .tut-timeline { grid-template-columns: 1fr; }
      .rule-points { grid-template-columns: 1fr; }
      .step-body { padding: 34px 18px 18px; }
      .os-panel-head { flex-wrap: wrap; }
    }

    @media (prefers-reduced-motion: reduce) {
      .reveal, .faq-a { transition: none; }
      .reveal { opacity: 1; transform: none; }
    }