/* roulang page: index */
:root {
      --ink: #12151A;
      --ink-soft: #2A2E35;
      --celadon: #2F6F5E;
      --celadon-deep: #24584A;
      --bronze: #B56A32;
      --bronze-deep: #934F22;
      --paper: #F3EFE6;
      --card: #FFFAF3;
      --line: #E4DDD0;
      --muted: #6B645A;
      --success: #2F6F5E;
      --warn: #B56A32;
      --white: #FFFaf3;
      --radius: 6px;
      --shadow: 0 8px 24px rgba(18, 21, 26, 0.06);
      --space-xs: 8px;
      --space-sm: 16px;
      --space-md: 28px;
      --space-lg: 48px;
      --space-xl: 88px;
      --space-2xl: 120px;
      --nav-h: 108px;
      --ease: 240ms ease;
      --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
      --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      --mono: "JetBrains Mono", "SFMono-Regular", ui-monospace, monospace;
      --max: 1240px;
    }
    *, *::before, *::after { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    html, body { margin: 0; padding: 0; }
    body {
      font-family: var(--sans);
      font-size: 17px;
      line-height: 1.75;
      color: var(--ink);
      background: var(--paper);
      background-image:
        radial-gradient(rgba(18,21,26,0.025) 0.6px, transparent 0.6px);
      background-size: 7px 7px;
    }
    img { max-width: 100%; display: block; height: auto; }
    a { color: var(--celadon); text-decoration: none; }
    button, input, select, textarea { font-family: inherit; }
    button { cursor: pointer; }
    h1, h2, h3 { font-family: var(--serif); font-weight: 600; letter-spacing: -0.02em; line-height: 1.22; color: var(--ink); margin: 0 0 16px; }
    h1 { font-size: clamp(32px, 5vw, 64px); }
    h2 { font-size: clamp(28px, 3.2vw, 38px); }
    h3 { font-size: clamp(20px, 2vw, 24px); }
    p { margin: 0 0 16px; color: var(--ink-soft); max-width: 42em; }
    :focus-visible { outline: 2px solid var(--bronze); outline-offset: 3px; }
    .container { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }
    section { scroll-margin-top: 108px; }
    .kicker {
      font-family: var(--mono);
      font-size: 12px;
      letter-spacing: 0.14em;
      color: var(--celadon);
      margin-bottom: 10px;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-family: var(--mono);
      font-size: 12px;
      border: 1px solid var(--line);
      padding: 6px 10px;
      border-radius: 4px;
      color: var(--ink-soft);
      background: rgba(255,250,243,0.7);
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 48px;
      padding: 0 22px;
      border-radius: 4px;
      border: 1px solid transparent;
      font-size: 15px;
      font-weight: 500;
      transition: transform var(--ease), background var(--ease), border-color var(--ease), color var(--ease);
      text-decoration: none;
    }
    .btn:active { transform: translateY(1px); }
    .btn-primary { background: var(--bronze); color: var(--paper); }
    .btn-primary:hover { background: var(--bronze-deep); }
    .btn-ghost { background: transparent; border-color: var(--ink); color: var(--ink); }
    .btn-ghost:hover { border-color: var(--celadon); color: var(--celadon); }
    .btn-light { background: var(--paper); color: var(--ink); }
    .btn-light:hover { background: #fff; }
    .text-link {
      position: relative;
      color: var(--celadon);
      font-weight: 500;
    }
    .text-link::after {
      content: "";
      position: absolute;
      left: 0; bottom: -2px;
      width: 100%; height: 2px;
      background: currentColor;
      transform: scaleX(0.28);
      transform-origin: left;
      transition: transform 280ms ease;
    }
    .text-link:hover::after { transform: scaleX(1); }
    .site-header {
      position: sticky;
      top: 0;
      z-index: 80;
      background: rgba(243,239,230,0.92);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid transparent;
      transition: box-shadow var(--ease), background var(--ease);
    }
    .site-header.is-compact {
      background: #12151A;
      box-shadow: 0 8px 24px rgba(18,21,26,0.18);
    }
    .site-header.is-compact .topbar,
    .site-header.is-compact .brand-mark,
    .site-header.is-compact .brand-sub,
    .site-header.is-compact .nav-links a,
    .site-header.is-compact .menu-toggle { color: var(--paper); }
    .site-header.is-compact .nav-links a:hover,
    .site-header.is-compact .nav-links a.is-active { color: #D7E7E0; }
    .topbar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 16px;
      min-height: 36px;
      font-size: 12px;
      color: var(--muted);
      border-bottom: 1px solid var(--line);
    }
    .topbar-left, .topbar-right { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
    .topbar a { color: inherit; }
    .trust-chip {
      font-family: var(--mono);
      border: 1px solid var(--line);
      padding: 2px 8px;
      color: var(--celadon-deep);
    }
    .site-header.is-compact .trust-chip { color: #D7E7E0; border-color: rgba(243,239,230,0.25); }
    .nav-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 20px;
      min-height: 72px;
      transition: min-height var(--ease);
    }
    .site-header.is-compact .nav-row { min-height: 60px; }
    .logo {
      display: flex;
      flex-direction: column;
      color: var(--ink);
      min-width: 132px;
    }
    .brand-mark {
      font-family: var(--serif);
      font-size: 22px;
      font-weight: 700;
      letter-spacing: 0.08em;
      color: var(--ink);
    }
    .brand-sub {
      font-family: var(--mono);
      font-size: 11px;
      color: var(--muted);
      letter-spacing: 0.18em;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 22px;
    }
    .nav-links a {
      color: var(--ink);
      font-size: 15px;
      position: relative;
    }
    .nav-links a::after {
      content: "";
      position: absolute;
      left: 0; bottom: -8px;
      height: 2px; width: 100%;
      background: var(--celadon);
      transform: scaleX(0);
      transition: transform var(--ease);
    }
    .nav-links a:hover::after, .nav-links a.is-active::after { transform: scaleX(1); }
    .menu-toggle {
      display: none;
      width: 44px; height: 44px;
      border: 1px solid var(--line);
      background: transparent;
      color: var(--ink);
    }
    .drawer {
      position: fixed;
      inset: 0 0 0 auto;
      width: min(86vw, 360px);
      background: var(--ink);
      color: var(--paper);
      transform: translateX(100%);
      transition: transform 280ms ease;
      z-index: 90;
      padding: 28px 24px 40px;
      display: flex;
      flex-direction: column;
      gap: 18px;
    }
    .drawer.is-open { transform: translateX(0); }
    .drawer a { color: var(--paper); font-size: 20px; font-family: var(--serif); min-height: 44px; display: flex; align-items: center; }
    .drawer-close {
      align-self: flex-end;
      width: 44px; height: 44px;
      border: 1px solid rgba(243,239,230,0.25);
      background: transparent;
      color: var(--paper);
    }
    .backdrop {
      position: fixed; inset: 0;
      background: rgba(18,21,26,0.45);
      opacity: 0; pointer-events: none;
      transition: opacity var(--ease);
      z-index: 85;
    }
    .backdrop.is-open { opacity: 1; pointer-events: auto; }
    .hero {
      position: relative;
      min-height: calc(100vh - 108px);
      overflow: hidden;
      color: var(--paper);
    }
    .hero-slide {
      position: absolute; inset: 0;
      background-size: cover;
      background-position: center;
      opacity: 0;
      transform: translateY(12px);
      transition: opacity 700ms ease, transform 700ms ease;
    }
    .hero-slide.is-active { opacity: 1; transform: none; z-index: 1; }
    .hero-mask {
      position: absolute; inset: 0;
      background: linear-gradient(90deg, rgba(18,21,26,0.82) 0%, rgba(18,21,26,0.48) 48%, rgba(18,21,26,0.28) 100%);
      z-index: 2;
    }
    .hero-content {
      position: relative;
      z-index: 3;
      min-height: calc(100vh - 108px);
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      align-items: end;
      padding: 72px 0 56px;
      gap: 40px;
    }
    .hero h1 { color: var(--paper); max-width: 9.4em; }
    .hero .lead {
      color: #E8E1D4;
      font-size: 16px;
      max-width: 36em;
      margin-bottom: 28px;
    }
    .hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 22px; }
    .hero-tags { display: flex; gap: 8px; flex-wrap: wrap; }
    .play-panel {
      justify-self: end;
      width: min(100%, 340px);
      border: 1px solid rgba(243,239,230,0.22);
      background: rgba(18,21,26,0.42);
      padding: 22px;
    }
    .play-btn {
      width: 72px; height: 72px;
      border-radius: 50%;
      border: 1px solid var(--paper);
      background: rgba(181,106,50,0.92);
      color: var(--paper);
      display: grid;
      place-items: center;
      margin-bottom: 16px;
    }
    .play-btn svg { margin-left: 4px; }
    .hero-ctrl {
      position: absolute;
      left: 0; right: 0; bottom: 18px;
      z-index: 4;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .hero-arrows { display: flex; gap: 8px; }
    .icon-btn {
      width: 44px; height: 44px;
      border: 1px solid rgba(243,239,230,0.35);
      background: transparent;
      color: var(--paper);
    }
    .progress {
      flex: 1;
      height: 2px;
      background: rgba(243,239,230,0.22);
      overflow: hidden;
    }
    .progress > span {
      display: block;
      height: 100%;
      width: 0;
      background: var(--bronze);
    }
    .split {
      display: grid;
      grid-template-columns: 7fr 5fr;
      gap: 48px;
      align-items: start;
    }
    .pain { padding: var(--space-2xl) 0; }
    .pain-list { display: grid; gap: 14px; }
    .pain-card {
      background: var(--card);
      border: 1px solid var(--line);
      padding: 20px 22px;
      border-radius: var(--radius);
      transition: transform var(--ease), border-color var(--ease);
    }
    .pain-card:hover { transform: translateY(-3px); border-color: var(--celadon); }
    .pain-card .label { font-family: var(--mono); font-size: 12px; color: var(--bronze); margin-bottom: 6px; }
    .solution { padding: var(--space-2xl) 0; background: #EFE9DC; }
    .solution-grid {
      display: grid;
      grid-template-columns: 8fr 4fr;
      gap: 36px;
      align-items: stretch;
    }
    .solution-photo {
      min-height: 460px;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius);
      position: relative;
    }
    .fact-stack {
      display: grid;
      gap: 12px;
      margin-top: 22px;
    }
    .fact {
      border-left: 2px solid var(--celadon);
      padding: 8px 0 8px 14px;
      font-size: 15px;
    }
    .syllabus { margin-top: 24px; border-top: 1px solid var(--line); }
    .syllabus-item { border-bottom: 1px solid var(--line); }
    .syllabus-item button {
      width: 100%;
      min-height: 48px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: none;
      border: 0;
      padding: 12px 0;
      color: var(--ink);
      font-size: 15px;
    }
    .syllabus-item .body { display: none; padding: 0 0 14px; color: var(--muted); font-size: 15px; }
    .syllabus-item.is-open .body { display: block; }
    .aside-card {
      background: var(--ink);
      color: var(--paper);
      padding: 28px 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .aside-card p { color: #D9D2C5; }
    .path { padding: var(--space-2xl) 0; }
    .timeline {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 18px;
      position: relative;
      margin-top: 36px;
    }
    .timeline::before {
      content: "";
      position: absolute;
      left: 0; right: 0; top: 22px;
      height: 1px;
      background: var(--line);
    }
    .step { position: relative; padding-top: 8px; }
    .step-no {
      font-family: var(--mono);
      font-size: 13px;
      color: var(--celadon);
      background: var(--paper);
      display: inline-block;
      padding-right: 8px;
      position: relative;
      z-index: 1;
    }
    .advantage { padding: var(--space-2xl) 0; background: #EFE9DC; }
    .grid-6 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 16px;
    }
    .adv-card {
      background: var(--card);
      border: 1px solid var(--line);
      padding: 24px 22px 22px;
      border-radius: var(--radius);
      transition: transform var(--ease), border-color var(--ease);
    }
    .adv-card:hover { transform: translateY(-3px); border-color: var(--celadon); }
    .adv-card svg { margin-bottom: 14px; }
    .courses { padding: var(--space-2xl) 0; }
    .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
    .course-card {
      background: var(--card);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      transition: transform var(--ease), border-color var(--ease);
    }
    .course-card:hover { transform: translateY(-3px); border-color: var(--celadon); }
    .course-card img { aspect-ratio: 16/10; object-fit: cover; width: 100%; }
    .course-body { padding: 20px 18px 22px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
    .meta-row { display: flex; gap: 8px; flex-wrap: wrap; }
    .dark-case {
      background: var(--ink);
      color: var(--paper);
      padding: var(--space-2xl) 0;
    }
    .dark-case h2, .dark-case h3 { color: var(--paper); }
    .quote-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 48px;
      align-items: center;
    }
    .giant-quote {
      font-family: var(--serif);
      font-size: clamp(28px, 3.6vw, 44px);
      line-height: 1.35;
      margin: 0;
    }
    .code-deco {
      font-family: var(--mono);
      font-size: 12px;
      color: #8FA79D;
      margin-bottom: 12px;
    }
    .case-box { border: 1px solid rgba(243,239,230,0.16); padding: 24px; }
    .outcomes { padding: var(--space-2xl) 0; }
    .num-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 28px;
    }
    .num-item .n {
      font-family: var(--mono);
      font-size: clamp(36px, 4vw, 52px);
      color: var(--bronze);
      line-height: 1;
    }
    .stories { padding: var(--space-2xl) 0; background: #EFE9DC; }
    .story-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
    .story-card {
      display: grid;
      grid-template-columns: 0.9fr 1.1fr;
      background: var(--card);
      border: 1px solid var(--line);
      overflow: hidden;
      min-height: 280px;
    }
    .story-card img { width: 100%; height: 100%; object-fit: cover; }
    .story-body { padding: 22px; }
    .quotes { padding: var(--space-2xl) 0; }
    .quote-masonry {
      display: grid;
      grid-template-columns: 1.3fr 1fr;
      grid-template-rows: auto auto;
      gap: 16px;
    }
    .q-card {
      background: var(--card);
      border: 1px solid var(--line);
      padding: 24px;
      border-radius: var(--radius);
    }
    .q-card.big { grid-row: span 2; }
    .who { padding: var(--space-2xl) 0; background: #EFE9DC; }
    .quad {
      display: grid;
      grid-template-columns: 1fr 1fr;
      border: 1px solid var(--line);
    }
    .quad-item {
      padding: 28px;
      background: var(--card);
      border-right: 1px solid var(--line);
      border-bottom: 1px solid var(--line);
    }
    .quad-item:nth-child(2n) { border-right: 0; }
    .quad-item:nth-child(n+3) { border-bottom: 0; }
    .news { padding: var(--space-2xl) 0; }
    .news-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 16px; }
    .news-card {
      background: var(--card);
      border: 1px solid var(--line);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      transition: transform var(--ease), border-color var(--ease);
    }
    .news-card:hover { transform: translateY(-3px); border-color: var(--celadon); }
    .news-card img { aspect-ratio: 16/10; object-fit: cover; width: 100%; }
    .news-card .pad { padding: 18px; }
    .metrics {
      background: var(--ink);
      color: var(--paper);
      padding: 28px 0;
    }
    .metrics-row {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 12px;
    }
    .m-item {
      border-left: 1px solid rgba(243,239,230,0.18);
      padding-left: 16px;
    }
    .m-item b { font-family: var(--mono); font-size: 22px; font-weight: 500; display: block; }
    .faq { padding: var(--space-2xl) 0; }
    .faq-item { border-bottom: 1px solid var(--line); }
    .faq-item button {
      width: 100%;
      min-height: 56px;
      text-align: left;
      background: none;
      border: 0;
      padding: 16px 8px;
      font-size: 17px;
      font-family: var(--serif);
      display: flex;
      justify-content: space-between;
      gap: 16px;
    }
    .faq-item .ans {
      max-height: 0;
      overflow: hidden;
      transition: max-height 280ms ease;
      color: var(--muted);
      padding: 0 8px;
    }
    .faq-item.is-open { border-left: 2px solid var(--celadon); }
    .faq-item.is-open .ans { max-height: 240px; padding-bottom: 16px; }
    .cta { padding: var(--space-2xl) 0; background: #E3EDE8; }
    .cta-grid {
      display: grid;
      grid-template-columns: 0.9fr 1.1fr;
      gap: 40px;
      align-items: start;
    }
    .form {
      background: var(--card);
      border: 1px solid var(--line);
      padding: 24px;
      display: grid;
      gap: 14px;
    }
    .form label { font-size: 14px; color: var(--ink-soft); display: grid; gap: 6px; }
    .form input, .form select {
      min-height: 46px;
      border: 1px solid #C9C0B2;
      background: #F7F3EA;
      padding: 0 12px;
      color: var(--ink);
      border-radius: 4px;
    }
    .form input:focus, .form select:focus { border-color: var(--bronze); outline: none; }
    .form-error { color: var(--bronze); font-size: 13px; min-height: 18px; }
    .form-ok { display: none; color: var(--celadon-deep); font-size: 14px; }
    .site-footer {
      background: var(--ink);
      color: #C9C2B6;
      padding: 56px 0 24px;
      font-size: 14px;
    }
    .foot-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
      gap: 28px;
      margin-bottom: 36px;
    }
    .site-footer h3 { color: var(--paper); font-size: 18px; }
    .site-footer a { color: #C9C2B6; display: inline-block; min-height: 32px; }
    .site-footer a:hover { color: var(--paper); }
    .legal {
      border-top: 1px solid rgba(243,239,230,0.12);
      padding-top: 16px;
      display: flex;
      justify-content: space-between;
      gap: 12px;
      flex-wrap: wrap;
      font-size: 12px;
    }
    .reveal { opacity: 0; transform: translateY(16px); animation: none; }
    .reveal.in { opacity: 1; transform: none; transition: opacity 500ms ease, transform 500ms ease; }
    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      .hero-slide, .reveal, .progress > span, .faq-item .ans { transition: none !important; }
      .reveal { opacity: 1; transform: none; }
    }
    @media (max-width: 1440px) {
      :root { --max: 1200px; }
    }
    @media (max-width: 1024px) {
      .hero-content, .split, .solution-grid, .quote-grid, .cta-grid, .story-card, .news-grid, .quote-masonry { grid-template-columns: 1fr; }
      .timeline { grid-template-columns: 1fr 1fr; }
      .timeline::before { display: none; }
      .num-grid, .metrics-row, .grid-6 { grid-template-columns: 1fr 1fr; }
      .foot-grid { grid-template-columns: 1fr 1fr; }
      .play-panel { justify-self: start; }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-cta { display: none; }
      .menu-toggle { display: grid; place-items: center; }
      .topbar { font-size: 11px; }
      .grid-3, .story-grid, .quad, .num-grid, .metrics-row { grid-template-columns: 1fr; }
      .grid-6 { grid-template-columns: 1fr 1fr; }
      .story-card { grid-template-columns: 1fr; }
      section { scroll-margin-top: 96px; }
      .pain, .solution, .path, .advantage, .courses, .dark-case, .outcomes, .stories, .quotes, .who, .news, .faq, .cta { padding: 64px 0; }
    }
    @media (max-width: 520px) {
      .container { width: min(100% - 28px, var(--max)); }
      .grid-6, .timeline, .foot-grid { grid-template-columns: 1fr; }
      .hero-actions { flex-direction: column; }
      .btn { width: 100%; }
      h1 { font-size: 34px; }
      .topbar-left span:nth-child(2) { display: none; }
    }