/* 深蓝隧道 · 云通讯通话 */
:root {
  --void: #030814;
  --tunnel: #071433;
  --lane: #0c1f4a;
  --glow: #3ec7ff;
  --line: rgba(62, 199, 255, 0.28);
  --ink: #e6f4ff;
  --mute: #8aa8c8;
  --dial: #2f7cff;
  --pulse: #5dffd0;
  --warn: #ffb14a;
  --radius: 16px;
  --font-display: "Segoe UI Variable Display", "Bahnschrift", "Microsoft YaHei UI", sans-serif;
  --font-body: "Segoe UI", "Microsoft YaHei UI", sans-serif;
  --font-mono: "Cascadia Mono", "Consolas", monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-body);
  background: radial-gradient(1200px 600px at 50% -10%, rgba(47, 124, 255, 0.22), transparent 55%), var(--void);
  line-height: 1.65;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { font-family: var(--font-display); line-height: 1.2; margin: 0 0 0.55rem; }
p { margin: 0 0 0.85rem; }
.wrap { width: min(1120px, calc(100% - 2rem)); margin-inline: auto; }

/* vanishing tunnel rails */
.tunnel-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent 0 18%, rgba(62, 199, 255, 0.05) 18% 18.15%, transparent 18.15% 81.85%, rgba(62, 199, 255, 0.05) 81.85% 82%, transparent 82%),
    radial-gradient(ellipse 70% 40% at 50% 110%, rgba(47, 124, 255, 0.35), transparent 70%),
    linear-gradient(180deg, #04102a, var(--void) 45%, #02060f);
}
.tunnel-bg::before,
.tunnel-bg::after {
  content: "";
  position: absolute;
  left: 50%;
  width: 140vmax;
  height: 140vmax;
  transform: translateX(-50%);
  border: 1px solid rgba(62, 199, 255, 0.08);
  border-radius: 50%;
  top: 18%;
}
.tunnel-bg::after { top: 32%; width: 90vmax; height: 90vmax; border-color: rgba(62, 199, 255, 0.12); }

.app > * { position: relative; z-index: 1; }

/* top: call status bar */
.status-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0 0.35rem;
}
.carrier {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}
.signal {
  width: 38px; height: 38px;
  border-radius: 12px;
  background: linear-gradient(145deg, #1a4a9a, #0a2458);
  display: grid;
  place-items: center;
  box-shadow: 0 0 0 1px var(--line), 0 0 20px rgba(62, 199, 255, 0.25);
  position: relative;
}
.signal::before {
  content: "";
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 12px var(--pulse);
  animation: blink 1.8s ease-in-out infinite;
}
@keyframes blink {
  0%, 100% { opacity: 0.45; }
  50% { opacity: 1; }
}
.carrier b { display: block; font-size: 1.08rem; }
.carrier small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--mute);
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.95rem;
  font-size: 0.92rem;
}
.nav a { color: var(--mute); }
.nav a:hover, .nav a.on { color: var(--ink); }
.nav a.on {
  text-shadow: 0 0 12px rgba(62, 199, 255, 0.45);
}
.call-chip {
  padding: 0.48rem 0.95rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(12, 31, 74, 0.75);
  color: var(--glow);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

/* HERO — tunnel mouth + dial panel */
.tunnel-hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 1.4rem;
  align-items: center;
  min-height: min(76vh, 700px);
  padding: 1.5rem 0 2.3rem;
}
.live {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--pulse);
  margin-bottom: 0.85rem;
  text-transform: uppercase;
}
.live i {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 10px var(--pulse);
  display: inline-block;
}
.tunnel-hero h1 {
  font-size: clamp(2rem, 4.1vw, 3.1rem);
  max-width: 10ch;
  letter-spacing: 0.01em;
}
.lead { color: var(--mute); font-size: 1.04rem; max-width: 40ch; }
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin: 1.2rem 0 1rem;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 148px;
  padding: 0.78rem 1.2rem;
  border-radius: 999px;
  font-weight: 700;
  white-space: nowrap;
  word-break: keep-all;
  writing-mode: horizontal-tb;
  border: 1px solid transparent;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-call {
  background: linear-gradient(120deg, var(--dial), #3ec7ff);
  color: #03101f;
  box-shadow: 0 12px 30px rgba(47, 124, 255, 0.35);
}
.btn-line {
  background: rgba(7, 20, 51, 0.8);
  border-color: var(--line);
  color: var(--ink);
}
.sys {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.6rem;
  max-width: 420px;
}
.sys p {
  margin: 0;
  padding: 0.65rem 0.8rem;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(7, 20, 51, 0.7);
  font-size: 0.86rem;
  color: var(--mute);
}
.sys b { display: block; color: var(--ink); font-size: 0.78rem; letter-spacing: 0.05em; }

.viewport {
  align-self: center;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background:
    radial-gradient(circle at 50% 120%, rgba(62, 199, 255, 0.18), transparent 50%),
    rgba(7, 20, 51, 0.85);
  overflow: hidden;
  box-shadow: 0 0 0 1px rgba(62, 199, 255, 0.08), 0 30px 60px rgba(0, 0, 0, 0.35);
  position: relative;
}
.viewport .rails {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent 49.5%, rgba(62, 199, 255, 0.2) 49.5% 50.5%, transparent 50.5%),
    repeating-linear-gradient(180deg, transparent 0 28px, rgba(62, 199, 255, 0.06) 28px 29px);
  mask-image: linear-gradient(180deg, transparent, #000 30%, #000 70%, transparent);
  opacity: 0.55;
}

/* sections */
.sec { padding: 3rem 0; }
.sec-h {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.85rem 1.1rem;
  align-items: end;
  margin-bottom: 1.4rem;
}
.sec-h .ch {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--glow);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  border-left: 1px solid var(--line);
  padding-left: 0.5rem;
}
.sec-h h2 { font-size: clamp(1.5rem, 2.6vw, 2.05rem); }
.sec-h p { margin: 0; color: var(--mute); max-width: 50ch; }

/* download as 4 tunnel lanes */
.lanes {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  perspective: 900px;
}
.lane {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(18, 48, 100, 0.55), rgba(7, 20, 51, 0.95));
  padding: 1.1rem 1rem 1.15rem;
  display: grid;
  gap: 0.4rem;
  transform: rotateX(4deg);
  box-shadow: inset 0 1px 0 rgba(62, 199, 255, 0.12);
}
.lane .ch-no {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--glow);
  letter-spacing: 0.08em;
}
.lane .os { font-size: 1.15rem; margin: 0; }
.lane .meta { margin: 0; color: var(--mute); font-size: 0.88rem; }
.lane .meta b { color: var(--ink); }
.lane .btn { width: 100%; min-width: 0; margin-top: 0.4rem; }

/* feature waveform modules */
.wave-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: rgba(7, 20, 51, 0.7);
}
.mod {
  padding: 1.2rem 0.95rem 1.3rem;
  border-right: 1px solid var(--line);
  text-align: center;
}
.mod:last-child { border-right: 0; }
.mod .ico {
  width: 46px; height: 46px;
  margin: 0 auto 0.75rem;
  border-radius: 14px;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  background: radial-gradient(circle at 40% 30%, rgba(62, 199, 255, 0.35), transparent 60%), #0a1f4a;
  color: var(--glow);
  font-weight: 800;
}
.mod h3 { font-size: 1rem; }
.mod p { margin: 0; color: var(--mute); font-size: 0.86rem; }
.bars {
  display: flex;
  justify-content: center;
  align-items: end;
  gap: 3px;
  height: 18px;
  margin-bottom: 0.65rem;
}
.bars span {
  width: 3px;
  background: var(--glow);
  border-radius: 2px;
  animation: eq 1.1s ease-in-out infinite;
}
.bars span:nth-child(1) { height: 6px; animation-delay: 0s; }
.bars span:nth-child(2) { height: 12px; animation-delay: 0.15s; }
.bars span:nth-child(3) { height: 8px; animation-delay: 0.3s; }
.bars span:nth-child(4) { height: 16px; animation-delay: 0.1s; }
.bars span:nth-child(5) { height: 7px; animation-delay: 0.25s; }
@keyframes eq {
  0%, 100% { transform: scaleY(0.55); opacity: 0.55; }
  50% { transform: scaleY(1); opacity: 1; }
}

/* bridge solution */
.bridge {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 1.2rem;
}
.bridge-copy {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.3rem;
  background: rgba(7, 20, 51, 0.8);
}
.bridge-copy h2 { font-size: 1.6rem; }
.bridge-copy p { color: var(--mute); }
.bridge-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}
.bridge-list li {
  display: grid;
  grid-template-columns: 16px 1fr;
  gap: 0.55rem;
  align-items: start;
  font-size: 0.95rem;
}
.bridge-list li::before {
  content: "";
  width: 8px; height: 8px;
  margin-top: 0.45rem;
  border-radius: 50%;
  background: var(--glow);
  box-shadow: 0 0 10px var(--glow);
}
.gallery {
  display: grid;
  grid-template-rows: 1.15fr auto;
  gap: 0.7rem;
}
.shot {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #071433;
}
.shot-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.7rem;
}

/* trust ring */
.ring {
  text-align: center;
  padding: 2.1rem 1.2rem;
  border-radius: calc(var(--radius) + 8px);
  border: 1px solid var(--line);
  background:
    radial-gradient(circle at 50% 0%, rgba(62, 199, 255, 0.16), transparent 50%),
    rgba(7, 20, 51, 0.85);
}
.ring .big {
  font-size: clamp(1.7rem, 3.2vw, 2.45rem);
  margin-bottom: 0.3rem;
}
.ring .big em {
  font-style: normal;
  color: var(--glow);
  text-shadow: 0 0 18px rgba(62, 199, 255, 0.45);
}
.ring .sub { color: var(--mute); margin-bottom: 1.2rem; }
.brands {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.55rem;
}
.brands span {
  padding: 0.42rem 0.9rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(12, 31, 74, 0.8);
  font-size: 0.9rem;
}

/* call log + FAQ */
.split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 0.9rem;
}
.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(7, 20, 51, 0.78);
  overflow: hidden;
}
.panel-h {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 1rem 1.15rem;
  border-bottom: 1px solid var(--line);
}
.panel-h h2 { font-size: 1.2rem; margin: 0; }
.panel-h a { color: var(--glow); font-size: 0.88rem; }
.log {
  display: grid;
  grid-template-columns: 78px 1fr;
  gap: 0.75rem;
  padding: 0.9rem 1.15rem;
  border-bottom: 1px solid rgba(62, 199, 255, 0.12);
}
.log:last-child { border-bottom: 0; }
.log time {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--glow);
}
.log h3 { font-size: 0.98rem; margin-bottom: 0.2rem; }
.log p { margin: 0; color: var(--mute); font-size: 0.88rem; }
.faq details {
  padding: 0.85rem 1.15rem;
  border-bottom: 1px solid rgba(62, 199, 255, 0.12);
}
.faq details:last-child { border-bottom: 0; }
.faq summary {
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: "▷ ";
  color: var(--glow);
  font-family: var(--font-mono);
  font-size: 0.8rem;
}
.faq details[open] summary::before { content: "▼ "; }
.faq p { color: var(--mute); margin: 0.5rem 0 0.1rem; font-size: 0.92rem; }

/* reconnect CTA */
.reconnect {
  margin: 0.5rem 0 2.8rem;
  padding: 1.7rem 1.35rem;
  border-radius: calc(var(--radius) + 6px);
  border: 1px solid var(--line);
  background:
    radial-gradient(520px 180px at 85% 40%, rgba(62, 199, 255, 0.18), transparent 60%),
    radial-gradient(420px 160px at 10% 60%, rgba(47, 124, 255, 0.2), transparent 55%),
    rgba(7, 20, 51, 0.9);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 1.1rem;
  align-items: center;
}
.reconnect h2 { font-size: clamp(1.35rem, 2.3vw, 1.85rem); }
.gains {
  list-style: none;
  margin: 0.85rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}
.gains li {
  color: var(--mute);
  padding-left: 1rem;
  position: relative;
  font-size: 0.95rem;
}
.gains li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.55rem;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 8px var(--pulse);
}

.foot {
  border-top: 1px solid var(--line);
  padding: 1.3rem 0 2rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  color: var(--mute);
  font-size: 0.88rem;
}
.foot nav { display: flex; gap: 1rem; }

.page-hero {
  display: grid;
  grid-template-columns: 1fr 0.9fr;
  gap: 1.2rem;
  align-items: center;
  padding: 1.5rem 0 1rem;
}
.page-hero h1 { font-size: clamp(1.75rem, 3.4vw, 2.5rem); max-width: 12ch; }

@media (max-width: 980px) {
  .tunnel-hero, .bridge, .split, .reconnect, .page-hero { grid-template-columns: 1fr; }
  .lanes { grid-template-columns: 1fr 1fr; perspective: none; }
  .lane { transform: none; }
  .wave-grid { grid-template-columns: 1fr 1fr; }
  .mod { border-bottom: 1px solid var(--line); }
  .mod:nth-child(even) { border-right: 0; }
  .call-chip { display: none; }
}
@media (max-width: 640px) {
  .lanes, .wave-grid, .sys, .shot-row { grid-template-columns: 1fr; }
  .mod { border-right: 0 !important; }
  .sec-h { grid-template-columns: 1fr; }
  .sec-h .ch { writing-mode: horizontal-tb; transform: none; border-left: 0; border-bottom: 1px solid var(--line); padding: 0 0 0.3rem; width: max-content; }
  .actions .btn { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .signal::before, .bars span { animation: none; }
}

/* ===== Hero image hard rules ===== */
.tunnel-hero,
.page-hero { align-items: center; }
.viewport {
  align-self: center;
  height: auto;
  padding: 0;
  margin: 0;
}
.viewport img,
.hero-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
  object-position: center;
  margin: 0;
  padding: 0;
  min-height: 0;
  max-height: none;
  clip-path: none;
  transform: none;
}