/* 光束穿透 · 云端备份云盘 */
:root {
  --bg: #e8f4fb;
  --sky: #f4fbff;
  --ink: #1d3348;
  --mute: #5f7a90;
  --line: #c9e0ef;
  --beam: #ffe8a8;
  --sun: #f0c45c;
  --cloud: #ffffff;
  --cyan: #3aa7d4;
  --cyan-deep: #1f84ad;
  --ok: #4eaf8f;
  --shadow: 0 18px 40px rgba(40, 100, 140, 0.1);
  --radius: 20px;
  --font-display: "Segoe UI Variable Display", "Yu Gothic UI", "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(1000px 420px at 50% -8%, rgba(255, 232, 168, 0.55), transparent 55%),
    radial-gradient(800px 480px at 10% 20%, rgba(58, 167, 212, 0.16), transparent 55%),
    radial-gradient(700px 420px at 90% 10%, rgba(255, 255, 255, 0.8), transparent 50%),
    linear-gradient(180deg, #f7fcff, var(--bg) 45%, #e3f0f8);
  line-height: 1.68;
  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: 1.22; margin: 0 0 0.55rem; font-weight: 700; }
p { margin: 0 0 0.85rem; }
.wrap { width: min(1100px, calc(100% - 2rem)); margin-inline: auto; }

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

/* light beams */
.beams {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}
.beams span {
  position: absolute;
  top: -10%;
  width: 2px;
  height: 70%;
  background: linear-gradient(180deg, rgba(255, 232, 168, 0.85), transparent);
  filter: blur(1px);
  transform-origin: top;
  opacity: 0.55;
}
.beams span:nth-child(1) { left: 18%; transform: rotate(8deg); }
.beams span:nth-child(2) { left: 42%; width: 3px; transform: rotate(-4deg); opacity: 0.7; }
.beams span:nth-child(3) { left: 58%; transform: rotate(3deg); }
.beams span:nth-child(4) { left: 78%; transform: rotate(-7deg); height: 55%; }

/* top bar */
.vault-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.05rem 0 0.4rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}
.disk {
  width: 42px; height: 42px;
  border-radius: 50%;
  background:
    radial-gradient(circle at 35% 30%, #fff 0 10%, transparent 11%),
    linear-gradient(145deg, #9ad6ef, var(--cyan-deep));
  box-shadow: 0 0 0 3px rgba(255,255,255,0.7), var(--shadow);
  position: relative;
}
.disk::after {
  content: "";
  position: absolute;
  inset: 10px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.45);
}
.brand b { display: block; font-size: 1.08rem; }
.brand 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 { font-weight: 700; }
.sync-btn {
  padding: 0.5rem 1rem;
  border-radius: 999px;
  background: linear-gradient(120deg, var(--cyan), var(--cyan-deep));
  color: #fff;
  font-weight: 700;
  font-size: 0.86rem;
  white-space: nowrap;
  box-shadow: 0 10px 24px rgba(31, 132, 173, 0.28);
}

/* HERO — cloud vault */
.vault-hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 1.25rem;
  align-items: center;
  min-height: min(74vh, 700px);
  padding: 1.4rem 0 2.2rem;
}
.vault {
  background: rgba(255,255,255,0.72);
  border: 1px solid rgba(255,255,255,0.9);
  border-radius: calc(var(--radius) + 6px);
  box-shadow: var(--shadow);
  padding: 1.45rem 1.35rem 1.5rem;
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
}
.vault::before {
  content: "";
  position: absolute;
  left: 18%;
  top: -20%;
  width: 90px;
  height: 140%;
  background: linear-gradient(180deg, rgba(255, 232, 168, 0.45), transparent);
  transform: rotate(12deg);
  pointer-events: none;
}
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--cyan-deep);
  margin-bottom: 0.85rem;
  text-transform: uppercase;
}
.tag i {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--sun);
  box-shadow: 0 0 0 4px rgba(240, 196, 92, 0.25);
  display: inline-block;
}
.vault-hero h1 {
  font-size: clamp(1.95rem, 3.9vw, 3rem);
  max-width: 10ch;
  letter-spacing: -0.02em;
}
.lead { color: var(--mute); font-size: 1.03rem; max-width: 40ch; }
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin: 1.15rem 0 0.95rem;
}
.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;
}
.btn:hover { transform: translateY(-2px); }
.btn-sky {
  background: linear-gradient(120deg, #4eb5dd, var(--cyan-deep));
  color: #fff;
  box-shadow: 0 12px 26px rgba(31, 132, 173, 0.28);
}
.btn-cloud {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
}
.req {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.55rem;
}
.req p {
  margin: 0;
  padding: 0.65rem 0.8rem;
  border-radius: 14px;
  background: rgba(255,255,255,0.8);
  border: 1px solid var(--line);
  font-size: 0.86rem;
  color: var(--mute);
}
.req b { display: block; color: var(--ink); font-size: 0.78rem; }

.media {
  align-self: center;
  border-radius: calc(var(--radius) + 8px);
  border: 1px solid rgba(255,255,255,0.95);
  background: rgba(255,255,255,0.55);
  overflow: hidden;
  box-shadow: var(--shadow);
  position: relative;
}
.media::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(255, 232, 168, 0.18), transparent 40%);
  pointer-events: none;
  z-index: 1;
}

/* sections */
.sec { padding: 2.8rem 0; }
.head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: end;
  gap: 0.8rem 1.4rem;
  margin-bottom: 1.3rem;
}
.head h2 { font-size: clamp(1.45rem, 2.5vw, 1.95rem); margin: 0; }
.head p { margin: 0; color: var(--mute); max-width: 44ch; }
.k {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--cyan-deep);
  margin-bottom: 0.25rem;
}

/* download as storage vaults */
.drives {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.8rem;
}
.drive {
  background: rgba(255,255,255,0.78);
  border: 1px solid rgba(255,255,255,0.95);
  border-radius: var(--radius);
  padding: 1.15rem 1.05rem 1.2rem;
  box-shadow: var(--shadow);
  display: grid;
  gap: 0.4rem;
  position: relative;
  overflow: hidden;
}
.drive::after {
  content: "";
  position: absolute;
  right: -20px; top: -30px;
  width: 90px; height: 140px;
  background: linear-gradient(180deg, rgba(255, 232, 168, 0.35), transparent);
  transform: rotate(18deg);
  pointer-events: none;
}
.drive .cap {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--cyan-deep);
  letter-spacing: 0.08em;
}
.drive .os { font-size: 1.12rem; margin: 0; position: relative; }
.drive .meta { margin: 0; color: var(--mute); font-size: 0.88rem; position: relative; }
.drive .meta b { color: var(--ink); }
.drive .btn { width: 100%; min-width: 0; margin-top: 0.4rem; position: relative; }

/* feature cloud modules */
.mods {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.7rem;
}
.mod {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 1.05rem 0.9rem 1.1rem;
  box-shadow: var(--shadow);
}
.mod .ico {
  width: 42px; height: 42px;
  border-radius: 14px;
  display: grid; place-items: center;
  background: linear-gradient(145deg, #e8f7fd, #dff0f8);
  color: var(--cyan-deep);
  font-weight: 800;
  margin-bottom: 0.6rem;
  border: 1px solid var(--line);
}
.mod h3 { font-size: 1rem; }
.mod p { margin: 0; color: var(--mute); font-size: 0.86rem; }

/* sync solution */
.sync {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 1.1rem;
}
.panel-copy {
  background: rgba(255,255,255,0.8);
  border: 1px solid rgba(255,255,255,0.95);
  border-radius: calc(var(--radius) + 2px);
  padding: 1.4rem 1.3rem;
  box-shadow: var(--shadow);
}
.panel-copy h2 { font-size: 1.55rem; }
.panel-copy p { color: var(--mute); }
.list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}
.list li {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 0.55rem;
  align-items: start;
  font-size: 0.95rem;
}
.list li::before {
  content: "";
  width: 10px; height: 10px;
  margin-top: 0.4rem;
  border-radius: 50%;
  background: var(--sun);
  box-shadow: 0 0 0 4px rgba(240, 196, 92, 0.2);
}
.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: #fff;
  box-shadow: var(--shadow);
}
.shot-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.7rem;
}

/* trust */
.trust {
  text-align: center;
  padding: 2rem 1.2rem;
  border-radius: calc(var(--radius) + 8px);
  background: linear-gradient(180deg, #fff, #eaf6fc);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.trust .big {
  font-size: clamp(1.6rem, 3vw, 2.35rem);
  margin-bottom: 0.3rem;
}
.trust .big em {
  font-style: normal;
  color: var(--cyan-deep);
}
.trust .sub { color: var(--mute); margin-bottom: 1.15rem; }
.brands {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}
.brands span {
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--line);
  font-size: 0.9rem;
}

/* log + help */
.split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 0.85rem;
}
.panel {
  background: rgba(255,255,255,0.85);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.panel-h {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.95rem 1.1rem;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #f3faff, #fff);
}
.panel-h h2 { font-size: 1.18rem; margin: 0; }
.panel-h a { color: var(--cyan-deep); font-size: 0.88rem; font-weight: 700; }
.row {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 0.75rem;
  padding: 0.9rem 1.1rem;
  border-bottom: 1px solid rgba(201, 224, 239, 0.8);
}
.row:last-child { border-bottom: 0; }
.row time {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--cyan-deep);
}
.row h3 { font-size: 0.98rem; margin-bottom: 0.2rem; }
.row p { margin: 0; color: var(--mute); font-size: 0.88rem; }
.faq details {
  padding: 0.85rem 1.1rem;
  border-bottom: 1px solid rgba(201, 224, 239, 0.8);
}
.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(--cyan);
}
.faq p { color: var(--mute); margin: 0.5rem 0 0.1rem; font-size: 0.92rem; }

/* backup CTA */
.backup {
  margin: 0.5rem 0 2.7rem;
  padding: 1.6rem 1.35rem;
  border-radius: calc(var(--radius) + 8px);
  background:
    radial-gradient(520px 180px at 85% 20%, rgba(255, 232, 168, 0.4), transparent 60%),
    radial-gradient(420px 160px at 10% 80%, rgba(58, 167, 212, 0.18), transparent 55%),
    #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 1rem;
  align-items: center;
}
.backup h2 { font-size: clamp(1.35rem, 2.3vw, 1.8rem); }
.gains {
  list-style: none;
  margin: 0.85rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}
.gains li {
  color: var(--mute);
  padding-left: 1.1rem;
  position: relative;
  font-size: 0.95rem;
}
.gains li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--ok);
  font-weight: 800;
}

.foot {
  border-top: 1px solid var(--line);
  padding: 1.25rem 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: 1.15rem;
  align-items: center;
  padding: 1.4rem 0 1rem;
}
.page-hero h1 { font-size: clamp(1.7rem, 3.3vw, 2.45rem); max-width: 12ch; }

@media (max-width: 980px) {
  .vault-hero, .sync, .split, .backup, .page-hero { grid-template-columns: 1fr; }
  .drives { grid-template-columns: 1fr 1fr; }
  .mods { grid-template-columns: 1fr 1fr; }
  .sync-btn { display: none; }
}
@media (max-width: 640px) {
  .drives, .mods, .req, .shot-row { grid-template-columns: 1fr; }
  .actions .btn { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .btn:hover { transform: none; }
}

/* ===== Hero image hard rules ===== */
.vault-hero,
.page-hero { align-items: center; }
.media {
  align-self: center;
  height: auto;
  padding: 0;
  margin: 0;
}
.media 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;
  position: relative;
  z-index: 0;
}
/* no overlay on hero media */
.media::before { display: none; }