:root {
      color-scheme: dark;
      --bg: #08080b;
      --surface: rgba(255, 255, 255, .065);
      --text: #f5f6f8;
      --muted: #9ca0ad;
      --subtle: #777b88;
      --line: rgba(255, 255, 255, .12);
      --accent-a: #9a82ff;
      --accent-b: #48ddff;
      --accent-c: #ff73bd;
      --positive: #63e99a;
      --shadow: 0 28px 90px rgba(0, 0, 0, .32);
      --radius-lg: 34px;
      --radius-md: 24px;
      --ease: cubic-bezier(.2, .8, .2, 1);
    }

    * { box-sizing: border-box; }
    html {
      min-width: 320px;
      scroll-behavior: smooth;
      scroll-padding-top: 112px;
      background: var(--bg);
      overflow-x: hidden;
    }
    body {
      margin: 0;
      min-width: 320px;
      overflow-x: hidden;
      background:
        radial-gradient(circle at 8% 6%, rgba(154, 130, 255, .11), transparent 25%),
        radial-gradient(circle at 92% 28%, rgba(72, 221, 255, .08), transparent 27%),
        linear-gradient(180deg, #08080b 0%, #09090d 50%, #07070a 100%);
      color: var(--text);
      font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Microsoft YaHei", sans-serif;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }
    body.modal-open { overflow: hidden; }
    a { color: inherit; }
    button { color: inherit; font: inherit; }
    img { max-width: 100%; }
    ::selection { background: rgba(154, 130, 255, .35); color: #fff; }

    .page-noise {
      position: fixed;
      inset: 0;
      z-index: -1;
      pointer-events: none;
      opacity: .12;
      background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.16'/%3E%3C/svg%3E");
      mix-blend-mode: soft-light;
    }
    .ambient {
      position: fixed;
      width: 46vw;
      aspect-ratio: 1;
      border-radius: 50%;
      filter: blur(90px);
      opacity: .11;
      z-index: -2;
      pointer-events: none;
    }
    .ambient.a { left: -20vw; top: 18vh; background: var(--accent-a); }
    .ambient.b { right: -23vw; top: 48vh; background: var(--accent-b); }

    .scroll-progress {
      position: fixed;
      top: 0;
      left: 0;
      z-index: 1001;
      width: 100%;
      height: 2px;
      transform: scaleX(0);
      transform-origin: 0 50%;
      background: linear-gradient(90deg, var(--accent-c), var(--accent-a), var(--accent-b));
    }

    .container { width: min(1160px, calc(100% - 48px)); margin-inline: auto; }
    .glass {
      background: linear-gradient(145deg, rgba(255, 255, 255, .09), rgba(255, 255, 255, .035));
      border: 1px solid var(--line);
      box-shadow: inset 0 1px 0 rgba(255, 255, 255, .16), var(--shadow);
      backdrop-filter: blur(28px) saturate(145%);
      -webkit-backdrop-filter: blur(28px) saturate(145%);
    }

    .site-header {
      position: fixed;
      z-index: 1000;
      top: max(16px, env(safe-area-inset-top));
      left: 50%;
      transform: translateX(-50%);
      width: min(1080px, calc(100% - 32px));
      min-height: 64px;
      display: flex;
      align-items: center;
      gap: 14px;
      padding: 0;
      border-radius: 23px;
      transition: background .3s ease, border-color .3s ease;
    }
    .site-header > .glass-surface__content {
      justify-content: flex-start;
      gap: 14px;
      padding: 9px 10px 9px 16px;
    }
    .site-header.is-scrolled {
      --glass-frost: .13;
      border-color: rgba(255, 255, 255, .16);
    }
    .brand {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      min-width: max-content;
      text-decoration: none;
      font-size: 14px;
      font-weight: 690;
      letter-spacing: -.02em;
    }
    .brand-mark {
      width: 29px;
      aspect-ratio: 1;
      border-radius: 10px;
      background:
        radial-gradient(circle at 30% 26%, rgba(255, 255, 255, .95), transparent 15%),
        linear-gradient(135deg, var(--accent-c), var(--accent-a) 50%, var(--accent-b));
      box-shadow: 0 8px 24px rgba(118, 97, 255, .28), inset 0 0 0 1px rgba(255, 255, 255, .25);
    }
    .nav-wrap { flex: 1; min-width: 0; overflow-x: auto; scrollbar-width: none; }
    .nav-wrap::-webkit-scrollbar { display: none; }
    .nav-links {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 3px;
      min-width: max-content;
    }
    .nav-links a {
      display: inline-flex;
      align-items: center;
      min-height: 40px;
      padding: 0 14px;
      border-radius: 999px;
      color: #b4b7c0;
      text-decoration: none;
      font-size: 13px;
      transition: color .25s ease, background .25s ease, transform .25s var(--ease);
    }
    .nav-links a:hover,
    .nav-links a.active { color: #fff; background: rgba(255, 255, 255, .09); }
    .nav-links a:active { transform: scale(.96); }

    .language-toggle {
      min-width: 76px;
      min-height: 42px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 0 14px;
      border: 1px solid rgba(255, 255, 255, .14);
      border-radius: 999px;
      background: rgba(255, 255, 255, .08);
      cursor: pointer;
      white-space: nowrap;
      font-size: 12px;
      font-weight: 650;
      transition: transform .25s var(--ease), background .25s ease;
    }
    .language-toggle:hover { background: rgba(255, 255, 255, .14); transform: translateY(-2px); }
    .language-toggle:active { transform: scale(.97); }

    .hero {
      min-height: 100svh;
      display: grid;
      align-items: center;
      padding: 145px 0 88px;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.15fr) minmax(320px, .85fr);
      gap: clamp(42px, 7vw, 90px);
      align-items: center;
    }
    .hero-copy { position: relative; z-index: 1; }
    .kicker {
      display: inline-flex;
      align-items: center;
      gap: 9px;
      width: fit-content;
      margin-bottom: 23px;
      padding: 8px 12px;
      border-radius: 999px;
      color: #c8cad2;
      background: rgba(255, 255, 255, .055);
      border: 1px solid rgba(255, 255, 255, .1);
      font-size: 12px;
      letter-spacing: .08em;
      text-transform: uppercase;
    }
    .kicker-dot {
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background: var(--positive);
      box-shadow: 0 0 15px rgba(99, 233, 154, .8);
    }
    h1, h2, h3, p { margin-top: 0; }
    .hero h1 {
      margin-bottom: 26px;
      max-width: 780px;
      font-size: clamp(60px, 8.4vw, 112px);
      line-height: .94;
      letter-spacing: -.07em;
      font-weight: 740;
    }
    .hero h1 .gradient {
      display: block;
      background: linear-gradient(105deg, #fff 5%, #e3dfff 37%, var(--accent-a) 59%, var(--accent-b) 85%, #fff 112%);
      background-size: 190% auto;
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      animation: gradientMove 9s ease-in-out infinite alternate;
    }
    @keyframes gradientMove { to { background-position: 100% 50%; } }
    .hero-lead {
      max-width: 650px;
      margin-bottom: 34px;
      color: var(--muted);
      font-size: clamp(17px, 2vw, 20px);
      line-height: 1.78;
      letter-spacing: -.015em;
    }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
    .button {
      min-height: 52px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 9px;
      padding: 0 20px;
      border: 0;
      border-radius: 999px;
      text-decoration: none;
      cursor: pointer;
      transition: transform .28s var(--ease), box-shadow .28s ease, background .28s ease;
    }
    .button.primary {
      color: #08080b;
      background: #fff;
      font-weight: 680;
      box-shadow: 0 16px 46px rgba(255, 255, 255, .14);
    }
    .button.secondary {
      color: #ecedf1;
      background: rgba(255, 255, 255, .065);
      border: 1px solid rgba(255, 255, 255, .12);
    }
    .button:hover { transform: translateY(-3px); }
    .button.primary:hover { box-shadow: 0 21px 58px rgba(72, 221, 255, .18); }
    .button.secondary:hover { background: rgba(255, 255, 255, .11); }
    .button:active { transform: scale(.97); }

    .hero-visual {
      position: relative;
      min-height: 480px;
      display: grid;
      place-items: center;
    }
    .orb {
      position: absolute;
      width: min(390px, 88%);
      aspect-ratio: 1;
      border-radius: 50%;
      background:
        radial-gradient(circle at 35% 26%, rgba(255, 255, 255, .9), transparent 7%),
        radial-gradient(circle at 34% 30%, rgba(255, 115, 189, .58), transparent 29%),
        radial-gradient(circle at 66% 70%, rgba(72, 221, 255, .56), transparent 32%),
        radial-gradient(circle at 48% 48%, rgba(154, 130, 255, .8), rgba(73, 55, 134, .55) 45%, rgba(10, 10, 14, .1) 72%);
      box-shadow: inset -30px -30px 80px rgba(0, 0, 0, .35), inset 18px 12px 35px rgba(255, 255, 255, .22), 0 0 110px rgba(127, 102, 255, .2);
      animation: orbFloat 7s ease-in-out infinite;
    }
    .orb::before,
    .orb::after {
      content: "";
      position: absolute;
      border: 1px solid rgba(255, 255, 255, .1);
      border-radius: 50%;
    }
    .orb::before { inset: -16%; transform: rotateX(68deg) rotateZ(-9deg); }
    .orb::after { inset: -29%; border-color: rgba(72, 221, 255, .08); transform: rotateX(68deg) rotateZ(24deg); }
    @keyframes orbFloat { 50% { transform: translateY(-16px) rotate(4deg); } }

    .section { padding: 108px 0; }
    .section.first-section { padding-top: 154px; }
    .section.compact { padding-top: 68px; }
    .section-head { max-width: 760px; margin-bottom: 42px; }
    .section-label {
      display: inline-flex;
      align-items: center;
      gap: 9px;
      margin-bottom: 15px;
      color: #afb2bd;
      font-size: 12px;
      letter-spacing: .11em;
      text-transform: uppercase;
    }
    .section-label::before {
      content: "";
      width: 28px;
      height: 1px;
      background: linear-gradient(90deg, var(--accent-a), transparent);
    }
    .section-title {
      margin-bottom: 16px;
      font-size: clamp(42px, 5vw, 68px);
      line-height: 1.04;
      letter-spacing: -.055em;
      font-weight: 710;
    }
    .section-intro {
      max-width: 680px;
      margin: 0;
      color: var(--muted);
      font-size: 16px;
      line-height: 1.82;
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, minmax(0, 1fr));
      gap: 20px;
    }
    .feature-card {
      position: relative;
      min-width: 0;
      min-height: 340px;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      padding: 28px;
      border-radius: var(--radius-lg);
      text-decoration: none;
      isolation: isolate;
      transition: transform .38s var(--ease), border-color .38s ease, box-shadow .38s ease;
    }
    .feature-card:hover {
      transform: translateY(-7px);
      border-color: rgba(255, 255, 255, .23);
      box-shadow: 0 34px 90px rgba(0, 0, 0, .35);
    }
    .feature-card::before {
      content: "";
      position: absolute;
      z-index: -1;
      width: 220px;
      height: 220px;
      right: -75px;
      top: -75px;
      border-radius: 50%;
      filter: blur(8px);
      opacity: .28;
      transition: transform .5s var(--ease), opacity .4s ease;
    }
    .feature-card:hover::before { transform: scale(1.15) translate(-8px, 8px); opacity: .42; }
    .feature-card.portal::before { background: radial-gradient(circle, var(--accent-a), transparent 68%); }
    .feature-card.canvas::before { background: radial-gradient(circle, var(--accent-b), transparent 68%); }
    .feature-card.system::before { background: radial-gradient(circle, var(--accent-c), transparent 68%); }
    .feature-top { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-bottom: 44px; }
    .feature-icon {
      width: 52px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border-radius: 17px;
      background: rgba(255, 255, 255, .08);
      border: 1px solid rgba(255, 255, 255, .13);
      box-shadow: inset 0 1px 0 rgba(255, 255, 255, .15);
    }
    .feature-arrow {
      width: 42px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border-radius: 50%;
      background: rgba(255, 255, 255, .07);
      border: 1px solid rgba(255, 255, 255, .1);
      transition: transform .3s var(--ease), background .3s ease;
    }
    .feature-card:hover .feature-arrow { transform: translate(3px, -3px); background: rgba(255, 255, 255, .14); }
    .feature-copy { margin-top: auto; min-width: 0; }
    .feature-copy h3 { margin-bottom: 13px; font-size: clamp(25px, 2.5vw, 32px); letter-spacing: -.035em; }
    .feature-copy p { margin-bottom: 20px; color: var(--muted); line-height: 1.75; }
    .tags { display: flex; flex-wrap: wrap; gap: 8px; }
    .tag {
      padding: 7px 10px;
      border-radius: 999px;
      background: rgba(255, 255, 255, .055);
      border: 1px solid rgba(255, 255, 255, .08);
      color: #c4c6ce;
      font-size: 11px;
    }
    .status-tag { display: inline-flex; align-items: center; gap: 7px; white-space: nowrap; }
    .status-tag::before {
      content: "";
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: #ffbf64;
      box-shadow: 0 0 12px rgba(255, 191, 100, .6);
    }

    .calendar-card {
      display: grid;
      grid-template-columns: minmax(0, 1.3fr) minmax(270px, .7fr);
      gap: 30px;
      padding: 25px;
      border-radius: var(--radius-lg);
      overflow: hidden;
    }
    .calendar-preview {
      position: relative;
      min-width: 0;
      aspect-ratio: 16 / 10;
      overflow: hidden;
      border: 0;
      border-radius: 24px;
      padding: 0;
      background: #13131a;
      cursor: zoom-in;
      box-shadow: 0 20px 55px rgba(0, 0, 0, .3);
    }
    .calendar-preview img {
      width: 100%;
      height: 100%;
      display: block;
      object-fit: cover;
      object-position: top center;
      transition: transform .65s var(--ease), filter .4s ease;
    }
    .calendar-preview:hover img { transform: scale(1.025); filter: brightness(.82); }
    .preview-overlay {
      position: absolute;
      inset: 0;
      display: grid;
      place-items: center;
      opacity: 0;
      background: radial-gradient(circle, rgba(7, 7, 10, .1), rgba(7, 7, 10, .5));
      transition: opacity .35s ease;
    }
    .calendar-preview:hover .preview-overlay,
    .calendar-preview:focus-visible .preview-overlay { opacity: 1; }
    .zoom-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 11px 15px;
      border-radius: 999px;
      background: rgba(10, 10, 14, .65);
      border: 1px solid rgba(255, 255, 255, .18);
      backdrop-filter: blur(12px);
    }
    .calendar-info { display: flex; flex-direction: column; justify-content: center; min-width: 0; padding: 16px 12px 16px 4px; }
    .calendar-info .mini-label { color: var(--accent-b); font-size: 12px; letter-spacing: .1em; text-transform: uppercase; }
    .calendar-info h3 { margin: 12px 0 16px; font-size: clamp(30px, 4vw, 46px); line-height: 1.08; letter-spacing: -.045em; }
    .calendar-info p { color: var(--muted); line-height: 1.75; }
    .calendar-meta { display: grid; gap: 10px; margin-top: 18px; }
    .meta-row { display: flex; align-items: center; gap: 10px; color: #c7c9d0; font-size: 13px; }
    .meta-row svg { flex: 0 0 auto; color: var(--subtle); }
    .credit { margin-top: auto; padding-top: 28px; color: var(--subtle); font-size: 12px; }

    .author-card {
      display: grid;
      grid-template-columns: minmax(220px, .62fr) minmax(0, 1.38fr);
      gap: clamp(28px, 5vw, 64px);
      align-items: center;
      padding: clamp(30px, 5vw, 56px);
      border-radius: var(--radius-lg);
      overflow: hidden;
    }
    .author-copy { min-width: 0; }
    .author-copy h2 {
      margin: 0;
      font-size: clamp(42px, 5vw, 68px);
      line-height: 1.02;
      letter-spacing: -.055em;
    }
    .contact-list { min-width: 0; display: grid; gap: 12px; }
    .email-button {
      width: 100%;
      min-width: 0;
      display: grid;
      grid-template-columns: 42px minmax(0, 1fr) auto;
      align-items: center;
      gap: 13px;
      min-height: 72px;
      padding: 11px 13px;
      border: 1px solid rgba(255, 255, 255, .11);
      border-radius: 20px;
      background: rgba(255, 255, 255, .055);
      cursor: pointer;
      text-align: left;
      transition: transform .3s var(--ease), background .3s ease, border-color .3s ease;
    }
    .email-button:hover { transform: translateY(-3px); background: rgba(255, 255, 255, .1); border-color: rgba(255, 255, 255, .19); }
    .email-icon {
      width: 42px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border-radius: 14px;
      background: rgba(255, 255, 255, .075);
    }
    .email-text { min-width: 0; overflow-wrap: anywhere; color: #eceef3; font-size: 13px; line-height: 1.45; }
    .copy-state {
      padding: 7px 9px;
      border-radius: 999px;
      background: rgba(255, 255, 255, .055);
      color: var(--muted);
      font-size: 11px;
      white-space: nowrap;
    }
    .email-button.copied .copy-state { color: #8cf0b2; background: rgba(99, 233, 154, .1); }

    footer { padding: 44px 0 max(44px, env(safe-area-inset-bottom)); color: var(--subtle); font-size: 12px; }
    .footer-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 20px;
      padding-top: 24px;
      border-top: 1px solid rgba(255, 255, 255, .08);
    }
    .back-top { color: #b8bbc4; text-decoration: none; }
    .back-top:hover { color: #fff; }

    .reveal {
      opacity: 0;
      transform: translateY(30px);
      filter: blur(8px);
      transition: opacity .8s ease, transform .8s var(--ease), filter .8s ease;
    }
    .reveal.in-view { opacity: 1; transform: none; filter: none; }

    .viewer {
      position: fixed;
      inset: 0;
      z-index: 2000;
      display: grid;
      grid-template-rows: auto 1fr auto;
      visibility: hidden;
      opacity: 0;
      background: rgba(3, 3, 5, .94);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      transition: opacity .28s ease, visibility .28s ease;
      touch-action: none;
    }
    .viewer.open { visibility: visible; opacity: 1; }
    .viewer-bar {
      z-index: 2;
      min-height: 70px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 15px;
      padding: max(12px, env(safe-area-inset-top)) 18px 8px;
      color: #c7c9d1;
    }
    .viewer-title { font-size: 13px; }
    .icon-button {
      width: 44px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border: 1px solid rgba(255, 255, 255, .14);
      border-radius: 50%;
      background: rgba(255, 255, 255, .07);
      cursor: pointer;
      transition: background .25s ease, transform .25s var(--ease);
    }
    .icon-button:hover { background: rgba(255, 255, 255, .14); transform: scale(1.05); }
    .viewer-stage { position: relative; min-height: 0; overflow: hidden; cursor: grab; touch-action: none; }
    .viewer-stage.dragging { cursor: grabbing; }
    .viewer-image {
      position: absolute;
      left: 50%;
      top: 50%;
      max-width: 92vw;
      max-height: calc(100% - 16px);
      width: auto;
      height: auto;
      user-select: none;
      -webkit-user-drag: none;
      transform-origin: center center;
      will-change: transform;
      pointer-events: none;
    }
    .viewer-controls {
      z-index: 2;
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 8px;
      padding: 10px 16px max(18px, env(safe-area-inset-bottom));
    }
    .viewer-controls .icon-button { width: 46px; }
    .zoom-value { min-width: 65px; text-align: center; color: #b8bbc4; font-size: 12px; }
    .viewer-help {
      position: absolute;
      left: 50%;
      bottom: 18px;
      transform: translateX(-50%);
      width: max-content;
      max-width: calc(100% - 32px);
      color: #737783;
      font-size: 11px;
      text-align: center;
      pointer-events: none;
    }

    .toast {
      position: fixed;
      z-index: 3000;
      left: 50%;
      bottom: max(24px, env(safe-area-inset-bottom));
      transform: translate(-50%, 20px);
      opacity: 0;
      width: max-content;
      max-width: calc(100% - 32px);
      padding: 11px 15px;
      border: 1px solid rgba(255, 255, 255, .15);
      border-radius: 999px;
      background: rgba(20, 20, 26, .82);
      color: #eef0f4;
      box-shadow: 0 16px 50px rgba(0, 0, 0, .35);
      backdrop-filter: blur(18px);
      pointer-events: none;
      font-size: 13px;
      text-align: center;
      transition: opacity .25s ease, transform .25s var(--ease);
    }
    .toast.show { opacity: 1; transform: translate(-50%, 0); }

    .external-dialog {
      position: fixed;
      inset: 0;
      z-index: 2400;
      display: grid;
      place-items: center;
      padding: 22px;
      visibility: hidden;
      opacity: 0;
      transition: opacity .25s ease, visibility .25s ease;
    }
    .external-dialog.open { visibility: visible; opacity: 1; }
    .external-backdrop {
      position: absolute;
      inset: 0;
      background: rgba(2, 2, 5, .76);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
    }
    .external-sheet {
      position: relative;
      z-index: 1;
      width: min(560px, 100%);
      max-height: min(760px, calc(100dvh - 44px));
      overflow: auto;
      padding: 30px;
      border-radius: 32px;
      box-shadow: 0 32px 100px rgba(0, 0, 0, .52);
      transform: translateY(18px) scale(.985);
      transition: transform .3s var(--ease);
    }
    .external-dialog.open .external-sheet { transform: none; }
    .external-close {
      position: absolute;
      top: 18px;
      right: 18px;
      width: 42px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border: 1px solid rgba(255, 255, 255, .13);
      border-radius: 50%;
      background: rgba(255, 255, 255, .065);
      color: #d9dbe2;
      cursor: pointer;
      transition: background .22s ease, transform .22s var(--ease);
    }
    .external-close:hover { background: rgba(255, 255, 255, .13); transform: scale(1.04); }
    .external-dialog-icon {
      width: 54px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      margin-bottom: 22px;
      border: 1px solid rgba(255, 255, 255, .13);
      border-radius: 18px;
      background: linear-gradient(145deg, rgba(154, 130, 255, .2), rgba(32, 199, 239, .12));
      color: #f3f4f8;
    }
    .external-sheet h2 {
      max-width: 440px;
      margin: 8px 52px 12px 0;
      font-size: clamp(31px, 5vw, 46px);
      line-height: .98;
      letter-spacing: -.045em;
    }
    .external-description {
      max-width: 500px;
      margin: 0 0 22px;
      color: #a8abb5;
      font-size: 15px;
      line-height: 1.75;
    }
    .external-site {
      display: grid;
      grid-template-columns: 42px minmax(0, 1fr);
      align-items: center;
      gap: 12px;
      margin-bottom: 22px;
      padding: 14px;
      border: 1px solid rgba(255, 255, 255, .1);
      border-radius: 18px;
      background: rgba(255, 255, 255, .045);
    }
    .external-site-mark {
      width: 42px;
      aspect-ratio: 1;
      display: grid;
      place-items: center;
      border-radius: 13px;
      background: rgba(255, 255, 255, .075);
      color: #dfe1e7;
    }
    .external-site-copy { min-width: 0; }
    .external-site-copy strong,
    .external-site-copy span { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
    .external-site-copy strong { margin-bottom: 3px; font-size: 14px; color: #f2f3f6; }
    .external-site-copy span { color: #7f838f; font-size: 11px; }
    .external-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
    .external-actions .button { width: 100%; min-height: 52px; justify-content: center; border-radius: 16px; }
    .external-copy {
      width: 100%;
      min-height: 44px;
      margin-top: 10px;
      border: 0;
      background: transparent;
      color: #bfc2cb;
      cursor: pointer;
      font-size: 13px;
      text-decoration: underline;
      text-decoration-color: rgba(255, 255, 255, .25);
      text-underline-offset: 4px;
    }
    .external-copy:hover { color: #fff; }
    .external-note {
      margin: 13px 2px 0;
      color: #747884;
      font-size: 11px;
      line-height: 1.6;
      text-align: center;
    }

    @media (max-width: 1000px) {
      .features-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
      .feature-card.system { grid-column: 1 / -1; min-height: 300px; }
      .author-card { grid-template-columns: 1fr; }
      .contact-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    }

    @media (max-width: 860px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-copy { max-width: 760px; }
      .hero-visual { min-height: 370px; }
      .orb { width: min(340px, 72vw); }
      .calendar-card { grid-template-columns: 1fr; }
      .calendar-info { padding: 12px 6px 6px; }
    }

    @media (max-width: 760px) {
      .container { width: min(100% - 32px, 1160px); }
      html { scroll-padding-top: 124px; }
      .site-header {
        top: max(10px, env(safe-area-inset-top));
        width: calc(100% - 20px);
        min-height: auto;
        display: flex;
        padding: 0;
        border-radius: 21px;
      }
      .site-header > .glass-surface__content {
        display: grid;
        grid-template-columns: 1fr auto;
        gap: 8px;
        padding: 9px;
      }
      .brand { min-width: 0; padding-left: 5px; }
      .brand > span:last-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
      .language-toggle { grid-column: 2; grid-row: 1; min-width: 68px; min-height: 40px; padding-inline: 12px; }
      .nav-wrap { grid-column: 1 / -1; grid-row: 2; width: 100%; }
      .nav-links { justify-content: flex-start; }
      .nav-links a { min-height: 36px; padding-inline: 12px; font-size: 12px; }
      .section { padding: 84px 0; }
      .section.first-section { padding-top: 174px; }
      .section-title { font-size: clamp(39px, 12vw, 56px); }
      .features-grid { grid-template-columns: 1fr; }
      .feature-card,
      .feature-card.system { grid-column: auto; min-height: 320px; padding: 24px; border-radius: 28px; }
      .calendar-card { padding: 14px; border-radius: 28px; }
      .calendar-preview { border-radius: 20px; }
      .author-card { grid-template-columns: 1fr; padding: 30px 20px; border-radius: 28px; }
      .author-copy h2 { font-size: clamp(38px, 12vw, 54px); }
      .contact-list { grid-template-columns: 1fr; }
      .email-button { grid-template-columns: 38px minmax(0, 1fr) auto; }
      .email-icon { width: 38px; border-radius: 12px; }
      .footer-inner { align-items: flex-start; flex-direction: column; }
      .viewer-title { max-width: 68vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
      .viewer-help { display: none; }
      .external-dialog { align-items: end; padding: 0; }
      .external-sheet {
        width: 100%;
        max-height: calc(100dvh - max(10px, env(safe-area-inset-top)));
        padding: 25px 20px max(22px, env(safe-area-inset-bottom));
        border-radius: 28px 28px 0 0;
        transform: translateY(32px);
      }
      .external-sheet h2 { font-size: clamp(31px, 10vw, 42px); }
      .external-actions { grid-template-columns: 1fr; }
    }

    @media (max-width: 430px) {
      .feature-copy h3 { font-size: 27px; }
      .email-button { grid-template-columns: 36px minmax(0, 1fr); }
      .email-icon { width: 36px; }
      .copy-state { grid-column: 2; justify-self: start; }
    }

    @media (hover: none) {
      .calendar-preview .preview-overlay {
        opacity: 1;
        align-items: end;
        justify-items: end;
        padding: 12px;
        background: linear-gradient(180deg, transparent 65%, rgba(0, 0, 0, .45));
      }
      .zoom-pill { padding: 8px 10px; font-size: 11px; }
    }

    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after {
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: .01ms !important;
      }
      .reveal { opacity: 1; transform: none; filter: none; }
    }

/* v4 feature and usability additions */
.header-actions { display: flex; align-items: center; gap: 8px; }
.first-section { min-height: min(780px, 92svh); display: flex; align-items: center; padding-bottom: 100px; }
.section-utility { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 24px; }
.greeting-chip, .network-badge {
  display: inline-flex; align-items: center; gap: 8px; min-height: 34px; padding: 0 12px;
  border: 1px solid rgba(255,255,255,.12); border-radius: 999px; background: rgba(255,255,255,.055); color: var(--muted); font-size: 13px;
}
.network-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--positive); box-shadow: 0 0 12px rgba(99,233,154,.7); }
.network-badge[data-status="offline"] .network-dot { background: #ff8ca8; box-shadow: 0 0 12px rgba(255,140,168,.55); }
.feature-card { position: relative; }
.feature-card .feature-copy { min-height: 190px; }
.feature-bottom { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 20px; }
.feature-details {
  min-height: 38px; padding: 0 14px; border: 1px solid rgba(255,255,255,.13); border-radius: 999px; background: rgba(255,255,255,.07); color: #fff; cursor: pointer; font-weight: 650;
}
.feature-details:hover { background: rgba(255,255,255,.14); }
.status-badge {
  display: inline-flex; align-items: center; gap: 7px; min-height: 30px; padding: 0 10px; border-radius: 999px; border: 1px solid rgba(255,255,255,.11); color: #d7dae3; background: rgba(255,255,255,.055); font-size: 12px; white-space: nowrap;
}
.status-badge::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: #63e99a; }
.status-badge[data-status="external"]::before { background: #68c9ff; }
.status-badge[data-status="development"]::before { background: #ffca68; }
.status-badge[data-status="offline"]::before { background: #ff819e; }
.detail-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
.detail-item { padding: 14px; border: 1px solid rgba(255,255,255,.1); border-radius: 16px; background: rgba(255,255,255,.045); }
.detail-item span { display: block; margin-bottom: 5px; color: var(--subtle); font-size: 12px; }
.detail-item strong { color: var(--text); font-size: 14px; }
.detail-purpose { margin: 0 0 18px; color: var(--muted); line-height: 1.65; }
.detail-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.calendar-toolbar { display: flex; align-items: end; justify-content: space-between; gap: 14px; margin-bottom: 18px; }
.calendar-version-field { display: grid; gap: 7px; width: min(420px,100%); }
.calendar-version-field label { color: var(--muted); font-size: 13px; }
.calendar-select { min-height: 44px; padding: 0 14px; border: 1px solid rgba(255,255,255,.13); border-radius: 14px; background: rgba(255,255,255,.06); color: #fff; }
.calendar-select option { background: #15141b; }
.calendar-version-actions { display: flex; gap: 8px; }
.calendar-version-actions button, .calendar-version-actions a { min-height: 42px; display: inline-flex; align-items: center; padding: 0 14px; border: 1px solid rgba(255,255,255,.12); border-radius: 999px; background: rgba(255,255,255,.06); color: #fff; text-decoration: none; cursor: pointer; }
.calendar-version-data { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 9px; margin-top: 20px; }
.calendar-version-data div { padding: 11px; border-radius: 14px; background: rgba(255,255,255,.045); }
.calendar-version-data span { display: block; color: var(--subtle); font-size: 11px; }
.calendar-version-data strong { display: block; margin-top: 4px; font-size: 13px; }
.contact-controls { display: grid; grid-template-columns: minmax(0,1fr) auto; gap: 12px; align-items: end; margin: 20px 0; }
.subject-field { display: grid; gap: 7px; }
.subject-field label { color: var(--muted); font-size: 13px; }
.contact-list { display: grid; gap: 10px; }
.contact-item { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 16px; border: 1px solid rgba(255,255,255,.1); border-radius: 18px; background: rgba(255,255,255,.045); }
.contact-main { min-width: 0; display: grid; gap: 5px; }
.contact-label { color: var(--subtle); font-size: 12px; }
.contact-address { overflow-wrap: anywhere; font-size: 14px; }
.contact-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 7px; }
.small-action { min-height: 36px; padding: 0 12px; border: 1px solid rgba(255,255,255,.12); border-radius: 999px; background: rgba(255,255,255,.06); color: #fff; cursor: pointer; font-size: 12px; }
.small-action.primary { background: #f5f5f7; color: #111; border-color: transparent; }
.feedback-trigger { min-height: 44px; padding: 0 16px; border: 1px solid rgba(255,255,255,.13); border-radius: 999px; background: rgba(255,255,255,.06); color: #fff; cursor: pointer; }
.feedback-form { display: grid; gap: 16px; }
.feedback-form label { display: grid; gap: 8px; color: #d9d9df; font-weight: 650; }
.feedback-form textarea { min-height: 120px; resize: vertical; padding: 13px; border: 1px solid rgba(255,255,255,.13); border-radius: 15px; background: rgba(255,255,255,.055); color: #fff; line-height: 1.55; }
.diagnostic-box { max-height: 220px; overflow: auto; padding: 13px; border-radius: 15px; background: rgba(0,0,0,.26); color: #aeb2be; font: 12px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace; white-space: pre-wrap; overflow-wrap: anywhere; }
.scroll-hint { position: fixed; z-index: 20; left: 50%; bottom: calc(18px + env(safe-area-inset-bottom)); display: inline-flex; align-items: center; gap: 8px; padding: 9px 13px; border: 1px solid rgba(255,255,255,.1); border-radius: 999px; background: rgba(8,8,12,.7); color: var(--muted); transform: translateX(-50%); cursor: pointer; -webkit-backdrop-filter: blur(15px); backdrop-filter: blur(15px); transition: opacity .25s ease, transform .25s ease; }
.scroll-hint.hidden { opacity: 0; transform: translate(-50%,12px); pointer-events: none; }
.footer-links { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.footer-links a, .footer-links button { color: var(--muted); background: none; border: 0; padding: 0; cursor: pointer; text-decoration: none; }
.footer-links a:hover, .footer-links button:hover { color: #fff; }
.archive-message { color: var(--muted); line-height: 1.65; }
@media (max-width: 820px) {
  .first-section { min-height: auto; padding-top: 150px; }
  .calendar-toolbar, .contact-controls { grid-template-columns: 1fr; display: grid; align-items: stretch; }
  .calendar-version-actions { flex-wrap: wrap; }
  .contact-item { align-items: flex-start; flex-direction: column; }
  .contact-actions { justify-content: flex-start; }
}
@media (max-width: 540px) {
  .detail-grid, .calendar-version-data { grid-template-columns: 1fr; }
  .scroll-hint { display: none; }
  .first-section { padding-top: 134px; }
}
.feature-copy h2 { margin: 0 0 14px; font-size: clamp(27px, 3vw, 36px); line-height: 1.08; letter-spacing: -.04em; }
.contact-area { min-width: 0; }
@media (max-width: 760px) {
  .header-actions { grid-column: 2; grid-row: 1; }
  .header-actions .language-toggle { min-width: 62px; min-height: 40px; padding-inline: 10px; }
  .header-actions .icon-only { width: 40px; height: 40px; }
}
@media (max-width: 390px) {
  .header-actions { gap: 5px; }
  .header-actions .language-toggle { min-width: 54px; padding-inline: 8px; }
}

.small-action { text-decoration: none; }

.feature-link-card { cursor: pointer; }
.feature-card-link {
  position: absolute;
  z-index: 1;
  inset: 0;
  border-radius: inherit;
}
.feature-card-link:focus-visible {
  outline: 2px solid rgba(154,130,255,.95);
  outline-offset: 5px;
}
.feature-link-card:has(.feature-card-link:focus-visible) {
  border-color: rgba(255,255,255,.28);
  box-shadow: 0 0 0 6px rgba(154,130,255,.13), 0 28px 80px rgba(0,0,0,.34);
}
.feature-link-card .feature-details,
.feature-link-card .small-action { position: relative; z-index: 2; }


/* v4.6 mobile navigation refinement
   Keep the same single-piece, single-row desktop glass architecture on phones.
   The centre links may scroll inside their own track on exceptionally narrow
   screens, while the page itself never gains horizontal overflow. */
@media (max-width: 760px) {
  html { scroll-padding-top: 96px; }

  .site-header {
    top: max(10px, env(safe-area-inset-top));
    width: calc(100% - 20px - env(safe-area-inset-left) - env(safe-area-inset-right));
    min-height: 60px;
    border-radius: 23px;
  }

  .site-header > .glass-surface__content {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: 6px;
    padding: 7px 8px;
  }

  .brand {
    grid-column: 1;
    grid-row: 1;
    gap: 7px;
    min-width: 0;
    padding-left: 2px;
    font-size: 13px;
  }

  .brand-mark {
    width: 27px;
    flex: 0 0 27px;
    border-radius: 9px;
  }

  .nav-wrap {
    grid-column: 2;
    grid-row: 1;
    width: auto;
    min-width: 0;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    -webkit-overflow-scrolling: touch;
    mask-image: linear-gradient(90deg, transparent 0, #000 7px, #000 calc(100% - 7px), transparent 100%);
    -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 7px, #000 calc(100% - 7px), transparent 100%);
  }

  .nav-links {
    justify-content: flex-start;
    gap: 1px;
    padding-inline: 5px;
  }

  .nav-links a {
    min-height: 36px;
    padding-inline: 8px;
    font-size: 11.5px;
    white-space: nowrap;
  }

  .header-actions {
    grid-column: 3;
    grid-row: 1;
    gap: 5px;
    min-width: max-content;
  }

  .header-actions .language-toggle {
    min-width: 58px;
    min-height: 38px;
    gap: 6px;
    padding-inline: 9px;
  }

  .header-actions .icon-only {
    width: 38px;
    height: 38px;
  }

  .section.first-section { padding-top: 126px; }
}

@media (max-width: 430px) {
  .header-actions .language-toggle {
    width: 38px;
    min-width: 38px;
    padding: 0;
  }

  .header-actions .language-toggle span { display: none; }
}

@media (max-width: 340px) {
  .brand > span:last-child { display: none; }
  .brand { gap: 0; }
  .nav-links a { padding-inline: 5px; font-size: 11px; }
}

/* Keep the requested “回到首页” label without clipping the existing one-row mobile navigation. */
@media (max-width: 390px) and (min-width: 341px) {
  .nav-links a { padding-inline: 6px; font-size: 11px; }
}