/* ============================================================
   telson.dev — design system
   hand-written, no framework, no external requests
   ============================================================ */

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

:root {
  --bg: #06090f;
  --bg-soft: #0a111d;
  --panel: #0c1424;
  --panel-2: #0f1a2e;
  --line: rgba(128, 158, 226, 0.14);
  --line-strong: rgba(128, 158, 226, 0.28);
  --text: #e9effc;
  --muted: #93a3c4;
  --dim: #64748f;
  --cyan: #2fd9ff;
  --purple: #8a5cff;
  --green: #3ddc97;
  --amber: #ffb454;
  --radius: 16px;
  --radius-sm: 10px;
  --maxw: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "Cascadia Code", "JetBrains Mono",
          Consolas, "Liberation Mono", monospace;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }

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

::selection { background: rgba(47, 217, 255, 0.28); }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- ambient background ---------- */

.bg-field {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(720px 480px at 78% -8%, rgba(138, 92, 255, 0.20), transparent 70%),
    radial-gradient(900px 520px at 12% 4%, rgba(47, 217, 255, 0.13), transparent 72%),
    radial-gradient(700px 600px at 50% 108%, rgba(47, 217, 255, 0.06), transparent 70%),
    var(--bg);
}

/* 顶部网格：只出现在页面最上方，向下柔和消失 */
.bg-grid {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: min(780px, 92vh);
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(128, 158, 226, 0.06) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(128, 158, 226, 0.06) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(to bottom, #000 0%, #000 34%, rgba(0, 0, 0, 0.45) 62%, transparent 88%);
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, #000 34%, rgba(0, 0, 0, 0.45) 62%, transparent 88%);
}

/* 指针高亮的网格（JS 渲染，覆盖 CSS 网格） */
.grid-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: min(780px, 92vh);
  z-index: -1;
  pointer-events: none;
  mask-image: linear-gradient(to bottom, #000 0%, #000 34%, rgba(0, 0, 0, 0.45) 62%, transparent 88%);
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, #000 34%, rgba(0, 0, 0, 0.45) 62%, transparent 88%);
}

body.has-canvas .bg-grid { display: none; }

/* ---------- layout ---------- */

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: clamp(64px, 9vw, 118px) 0; }
.section--tight { padding: clamp(44px, 6vw, 72px) 0; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan));
}

h1, h2, h3 { margin: 0; line-height: 1.18; letter-spacing: -0.02em; font-weight: 800; }

h1 { font-size: clamp(38px, 6.4vw, 68px); }
h2 { font-size: clamp(28px, 3.6vw, 40px); }
h3 { font-size: clamp(19px, 2vw, 22px); letter-spacing: -0.01em; }

p { margin: 0; }
.lead { color: var(--muted); font-size: clamp(16px, 1.6vw, 18px); line-height: 1.85; }
.muted { color: var(--muted); }
.dim { color: var(--dim); }

.section-head { max-width: 720px; margin-bottom: clamp(32px, 4vw, 52px); }
.section-head h2 { margin: 14px 0 16px; }

/* ---------- nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 60;
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease;
}

.nav.is-stuck {
  background: rgba(6, 9, 15, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}

.nav__inner {
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
  font-size: 17px;
}

.brand img { width: 26px; height: 26px; }
.brand span { color: var(--cyan); }

.nav__links {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav__link {
  padding: 8px 13px;
  border-radius: 999px;
  font-size: 14.5px;
  color: var(--muted);
  transition: color 0.2s ease, background 0.2s ease;
}

.nav__link:hover { color: var(--text); background: rgba(255, 255, 255, 0.05); }

.nav__link[aria-current="page"] {
  color: var(--text);
  background: rgba(47, 217, 255, 0.10);
  box-shadow: inset 0 0 0 1px rgba(47, 217, 255, 0.22);
}

.nav__link--cta {
  color: #041119;
  background: linear-gradient(120deg, var(--cyan), #67e8ff);
  font-weight: 700;
}

.nav__link--cta:hover { color: #041119; background: linear-gradient(120deg, #67e8ff, var(--cyan)); }

.nav__toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.25s ease, background 0.2s ease,
              border-color 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--primary {
  color: #041119;
  background: linear-gradient(120deg, var(--cyan), #6fe6ff 55%, #b388ff);
  box-shadow: 0 10px 30px -12px rgba(47, 217, 255, 0.7);
}

.btn--primary:hover { box-shadow: 0 14px 38px -12px rgba(47, 217, 255, 0.85); }

.btn--ghost {
  color: var(--text);
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.02);
}

.btn--ghost:hover { border-color: rgba(47, 217, 255, 0.45); background: rgba(47, 217, 255, 0.06); }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- hero ---------- */

.hero {
  position: relative;
  padding: clamp(56px, 8vw, 104px) 0 clamp(48px, 7vw, 88px);
}

.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}

.hero h1 { margin: 20px 0 22px; }

/* 会流动变色的渐变大字 */
h1 em {
  font-style: normal;
  background: linear-gradient(100deg,
    #2fd9ff 0%, #7fe9ff 14%, #9db8ff 30%, #8a5cff 48%,
    #c9a8ff 62%, #9db8ff 76%, #2fd9ff 100%);
  background-size: 300% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: gradient-pan 11s linear infinite;
  padding-right: 0.05em;
}

@keyframes gradient-pan {
  0% { background-position: 0% 50%; }
  100% { background-position: 300% 50%; }
}

.hero__lead { max-width: 560px; }

.hero .btn-row { margin-top: 30px; }

.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 30px; }

.chip {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.02);
}

/* framed hero visual */

.frame {
  position: relative;
  border-radius: 18px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(180deg, rgba(20, 32, 54, 0.9), rgba(8, 14, 24, 0.92));
  overflow: hidden;
  box-shadow:
    0 40px 90px -40px rgba(0, 0, 0, 0.9),
    0 0 0 1px rgba(255, 255, 255, 0.02) inset;
}

.frame__bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.02);
}

.frame__dot { width: 9px; height: 9px; border-radius: 50%; background: #2b3a55; }
.frame__dot:nth-child(1) { background: #ff6b6b80; }
.frame__dot:nth-child(2) { background: #ffb45480; }
.frame__dot:nth-child(3) { background: #3ddc9780; }

.frame__url {
  margin-left: 8px;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--dim);
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.frame__body { position: relative; aspect-ratio: 16 / 9; }
.frame__body img { width: 100%; height: 100%; object-fit: cover; }

.frame__glow {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(closest-side, rgba(47, 217, 255, 0.18), transparent 70%);
  filter: blur(20px);
}

.hero__visual { position: relative; }

.float-card {
  position: absolute;
  left: -18px;
  bottom: -22px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--line-strong);
  background: rgba(9, 16, 28, 0.92);
  backdrop-filter: blur(10px);
  box-shadow: 0 20px 50px -24px rgba(0, 0, 0, 0.9);
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--text);
}

.float-card .prompt { color: var(--green); }

/* ---------- cards / grids ---------- */

.grid { display: grid; gap: 18px; }
.grid > * { min-width: 0; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  position: relative;
  padding: 26px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.032), rgba(255, 255, 255, 0.008));
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}

.card:hover {
  border-color: rgba(47, 217, 255, 0.34);
  transform: translateY(-3px);
  background:
    linear-gradient(180deg, rgba(47, 217, 255, 0.06), rgba(255, 255, 255, 0.01));
}

.card h3 { margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; line-height: 1.8; }

.card__icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  margin-bottom: 18px;
  border: 1px solid var(--line);
  background: rgba(47, 217, 255, 0.08);
  color: var(--cyan);
  font-family: var(--mono);
  font-size: 16px;
}

.card__price {
  display: inline-block;
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--cyan);
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(47, 217, 255, 0.24);
  background: rgba(47, 217, 255, 0.07);
}

/* feature project card */

.feature {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
  gap: 0;
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  background: linear-gradient(180deg, rgba(14, 24, 40, 0.9), rgba(8, 13, 22, 0.9));
  overflow: hidden;
}

.feature__media { position: relative; min-height: 300px; background: #070c15; }
.feature__media img { width: 100%; height: 100%; object-fit: cover; }

.feature__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent 55%, rgba(8, 13, 22, 0.85));
}

.feature__body { padding: clamp(26px, 3.4vw, 44px); }

.feature__body h3 { font-size: clamp(24px, 2.6vw, 32px); margin: 10px 0 14px; }
.feature__body p { color: var(--muted); }

.tags { display: flex; flex-wrap: wrap; gap: 7px; margin: 20px 0 24px; }

.tag {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--muted);
  padding: 4px 9px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.025);
}

.link-row { display: flex; flex-wrap: wrap; gap: 18px; align-items: center; }

.textlink {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 14.5px;
  color: var(--cyan);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.textlink:hover { border-bottom-color: rgba(47, 217, 255, 0.5); }
.textlink--muted { color: var(--muted); }
.textlink--muted:hover { color: var(--text); border-bottom-color: var(--line-strong); }

/* ---------- code blocks ---------- */

.code {
  position: relative;
  max-width: 100%;
  margin: 0;
  padding: 18px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: #060b14;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.75;
  color: #c9d6f0;
  overflow-x: auto;
}

.code .c { color: #5d6f8e; }
.code .k { color: var(--purple); }
.code .s { color: var(--green); }
.code .n { color: var(--amber); }

.code__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.code__label {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--dim);
}

.copy {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11.5px;
  padding: 5px 10px;
  border-radius: 7px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.copy:hover { color: var(--cyan); border-color: rgba(47, 217, 255, 0.35); }
.copy.is-done { color: var(--green); border-color: rgba(61, 220, 151, 0.4); }

/* ---------- lists / bullets ---------- */

.ticks { list-style: none; margin: 0; padding: 0; display: grid; gap: 13px; }

.ticks li {
  position: relative;
  padding-left: 30px;
  color: var(--muted);
  font-size: 15.5px;
  line-height: 1.75;
}

.ticks li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 8px;
  width: 14px;
  height: 8px;
  border-left: 2px solid var(--green);
  border-bottom: 2px solid var(--green);
  transform: rotate(-45deg);
  opacity: 0.9;
}

.ticks strong { color: var(--text); font-weight: 700; }

.crosses li::before {
  border: 0;
  width: 12px;
  height: 12px;
  top: 7px;
  left: 3px;
  background:
    linear-gradient(45deg, transparent 44%, #ff6b81 44%, #ff6b81 56%, transparent 56%),
    linear-gradient(-45deg, transparent 44%, #ff6b81 44%, #ff6b81 56%, transparent 56%);
  transform: none;
}

/* ---------- steps ---------- */

.steps { display: grid; gap: 0; border-left: 1px solid var(--line); margin-left: 9px; }

.step { position: relative; padding: 0 0 34px 34px; }
.step:last-child { padding-bottom: 0; }

.step::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 217, 255, 0.1);
}

.step h3 { font-size: 17.5px; margin-bottom: 8px; }
.step p { color: var(--muted); font-size: 15px; }

.step__num {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--dim);
  letter-spacing: 0.12em;
  display: block;
  margin-bottom: 6px;
}

/* ---------- video ---------- */

.video {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line-strong);
  background: #05080e;
  aspect-ratio: 16 / 9;
  box-shadow: 0 40px 90px -50px rgba(0, 0, 0, 0.95);
}

.video iframe, .video video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* ---------- project page pieces ---------- */

.page-hero { padding: clamp(44px, 6vw, 76px) 0 clamp(28px, 4vw, 44px); }

.page-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.025);
}

.dot-live {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 10px rgba(61, 220, 151, 0.8);
}

.hero-logo {
  width: 76px;
  height: 76px;
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.03);
  padding: 6px;
  box-shadow: 0 18px 44px -22px rgba(47, 217, 255, 0.55);
}

.specs {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.spec { padding: 20px 22px; background: #080e18; }
.spec dt { font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--dim); margin-bottom: 8px; }
.spec dd { margin: 0; font-size: 15px; font-weight: 700; }

.gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }

.gallery figure {
  margin: 0;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: #070c15;
}

.gallery img { width: 100%; height: 100%; object-fit: cover; aspect-ratio: 16 / 9; }

.gallery figcaption {
  padding: 10px 12px;
  font-size: 12.5px;
  color: var(--dim);
  font-family: var(--mono);
  border-top: 1px solid var(--line);
}

/* ---------- FAQ ---------- */

.faq { border-top: 1px solid var(--line); }

.faq details {
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}

.faq summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 16.5px;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  font-family: var(--mono);
  color: var(--cyan);
  font-size: 18px;
  transition: transform 0.2s ease;
}

.faq details[open] summary::after { content: "−"; }

.faq p { margin-top: 12px; color: var(--muted); font-size: 15px; line-height: 1.8; }

/* ---------- contact / footer ---------- */

.contact-band {
  border-radius: 20px;
  border: 1px solid var(--line-strong);
  padding: clamp(30px, 4.5vw, 56px);
  background:
    radial-gradient(600px 300px at 85% 0%, rgba(138, 92, 255, 0.18), transparent 70%),
    radial-gradient(500px 300px at 5% 100%, rgba(47, 217, 255, 0.14), transparent 70%),
    linear-gradient(180deg, rgba(15, 26, 46, 0.9), rgba(8, 13, 22, 0.92));
}

.contact-band h2 { margin-bottom: 14px; }

.contact-list { display: flex; flex-wrap: wrap; gap: 10px 26px; margin-top: 26px; }

.contact-item {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text);
}

.contact-item span.label { color: var(--dim); }

.contact-item a:hover { color: var(--cyan); }

.footer {
  border-top: 1px solid var(--line);
  padding: 34px 0 44px;
  margin-top: clamp(50px, 7vw, 90px);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 13.5px;
  color: var(--dim);
}

.footer a:hover { color: var(--text); }

/* ---------- reveal animation ---------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn:hover, .card:hover { transform: none; }
}

/* ---------- lang toggle ---------- */

.lang-toggle {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.02);
}

.lang-toggle button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  padding: 6px 13px;
  cursor: pointer;
}

.lang-toggle button[aria-pressed="true"] {
  background: rgba(47, 217, 255, 0.14);
  color: var(--cyan);
}

/* ---------- responsive ---------- */

@media (max-width: 960px) {
  .hero__grid { grid-template-columns: minmax(0, 1fr); }
  .hero__visual { order: -1; max-width: 620px; }
  .feature { grid-template-columns: minmax(0, 1fr); }
  .feature__media { min-height: 220px; }
  .feature__media::after { background: linear-gradient(180deg, transparent 55%, rgba(8, 13, 22, 0.9)); }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .specs { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  body { font-size: 15.5px; }

  .nav__toggle { display: inline-flex; }

  .nav__links {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 14px 18px 20px;
    background: rgba(6, 9, 15, 0.97);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
  }

  .nav__links.is-open { display: flex; }
  .nav__link { padding: 12px 14px; border-radius: 10px; }
  .nav__link--cta { text-align: center; margin-top: 6px; }

  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .gallery { grid-template-columns: minmax(0, 1fr); }
  .float-card { left: 0; bottom: -18px; font-size: 11.5px; }
  .feature__body { padding: 24px 20px 28px; }
  .card { padding: 22px; }
  .code { font-size: 12.5px; }
  .contact-band { padding: 26px 22px; }
  .specs { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- copyable contact values + toast ---------- */

.contact-value {
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text);
  padding: 3px 9px;
  border-radius: 7px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  user-select: all;
}

.contact-item { gap: 8px; }
.contact-item .copy { margin-left: 2px; }

.copy {
  position: relative;
  z-index: 1;
  min-height: 30px;
  padding: 6px 12px;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

.copy:active { transform: translateY(1px); }

button.btn {
  appearance: none;
  -webkit-appearance: none;
  font-family: inherit;
}

.btn[data-copy] { cursor: pointer; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 30px;
  transform: translate(-50%, 0);
  max-width: min(92vw, 560px);
  padding: 11px 20px;
  border-radius: 999px;
  border: 1px solid rgba(47, 217, 255, 0.38);
  background: rgba(9, 16, 28, 0.97);
  color: var(--text);
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  text-align: center;
  box-shadow: 0 20px 46px -18px rgba(0, 0, 0, 0.95);
  opacity: 1;
  z-index: 300;
  pointer-events: none;
}

.toast.is-out { opacity: 0; transition: opacity 0.18s ease; }
.toast--err { border-color: rgba(255, 107, 129, 0.55); }
/* ============================================================
   灵动细节：滚动进度、卡片光斑、首屏浮动、终端打字
   ============================================================ */

/* 顶部滚动进度条 */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 80;
  pointer-events: none;
  background: transparent;
}

.scroll-progress i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--cyan), #9db8ff 55%, var(--purple));
  box-shadow: 0 0 14px rgba(47, 217, 255, 0.55);
  transition: width 0.1s linear;
}

/* 卡片跟随指针的光斑 */
.card,
.feature {
  position: relative;
  isolation: isolate;
}

.card::after,
.feature::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
  background: radial-gradient(320px circle at var(--mx, 50%) var(--my, 50%),
    rgba(47, 217, 255, 0.12), transparent 62%);
  opacity: 0;
  transition: opacity 0.35s ease;
  pointer-events: none;
}

.card:hover::after,
.feature:hover::after { opacity: 1; }

/* 首屏画面轻微浮动 */
@keyframes hero-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-9px); }
}

.hero__visual .frame { animation: hero-float 7.5s ease-in-out infinite; }

/* 终端打字光标 */
.float-card .cmd-slot { display: inline-block; min-width: 14ch; }

.float-card .caret {
  display: inline-block;
  width: 7px;
  height: 14px;
  margin-left: 1px;
  vertical-align: -2px;
  background: var(--cyan);
  opacity: 0.85;
  animation: caret-blink 1s steps(1) infinite;
}

@keyframes caret-blink { 50% { opacity: 0; } }

/* 减少动态效果 */
@media (prefers-reduced-motion: reduce) {
  h1 em { animation: none; background-position: 40% 50%; }
  .hero__visual .frame { animation: none; }
  .float-card .caret { animation: none; }
  .scroll-progress i { transition: none; }
}
/* ---------- 导航中的全站语言切换器 ---------- */
.nav__links .lang-toggle {
  margin-left: 8px;
  flex: 0 0 auto;
  align-self: center;
}

.nav__links .lang-toggle button {
  padding: 5px 11px;
  font-size: 11.5px;
  letter-spacing: 0.04em;
}

@media (max-width: 760px) {
  .nav__links .lang-toggle {
    margin: 10px 0 0;
    align-self: flex-start;
  }
}