:root {
  --bg: #f7f8f5;
  --panel: #ffffff;
  --ink: #101417;
  --muted: #5f6b67;
  --line: #dce3dd;
  --green: #1f8a5b;
  --teal: #0f766e;
  --blue: #2563eb;
  --amber: #d97706;
  --shadow: 0 24px 70px rgba(16, 20, 23, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
  background:
    linear-gradient(rgba(16, 20, 23, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16, 20, 23, 0.035) 1px, transparent 1px),
    var(--bg);
  background-size: 28px 28px;
}

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

code {
  padding: 2px 6px;
  border-radius: 6px;
  background: #eef3ef;
  color: #174536;
  font-family: Consolas, "SFMono-Regular", monospace;
  font-size: 0.95em;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1180px, calc(100% - 32px));
  margin: 14px auto 0;
  padding: 12px 14px;
  border: 1px solid rgba(220, 227, 221, 0.9);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 10px 35px rgba(16, 20, 23, 0.08);
  backdrop-filter: blur(14px);
}

.brand,
.nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--ink);
  color: white;
  font-weight: 900;
}

.nav {
  gap: 6px;
}

.nav a {
  padding: 9px 12px;
  border-radius: 8px;
  color: var(--muted);
  font-size: 14px;
}

.nav a[aria-current="page"],
.nav a:hover {
  background: #eef3ef;
  color: var(--ink);
}

.hero,
.page-hero,
.intro,
.feature-grid,
.band,
.guide-layout,
.faq {
  width: min(1180px, calc(100% - 32px));
  margin-inline: auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(420px, 1.05fr);
  gap: 50px;
  align-items: center;
  min-height: calc(100vh - 96px);
  padding: 58px 0 42px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 22px;
  font-size: clamp(38px, 6vw, 76px);
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-lead {
  margin-bottom: 8px;
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 800;
}

.hero-sub,
.page-hero p,
.intro p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-weight: 800;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  border-color: var(--ink);
  background: var(--ink);
  color: white;
  box-shadow: 0 14px 30px rgba(16, 20, 23, 0.16);
}

.button.ghost {
  background: rgba(255, 255, 255, 0.7);
}

.button.full {
  width: 100%;
}

.product-shot {
  min-width: 0;
}

.desktop-preview {
  position: relative;
  overflow: hidden;
  min-height: 520px;
  border: 1px solid rgba(16, 20, 23, 0.12);
  border-radius: 18px;
  background:
    radial-gradient(circle at 30% 20%, rgba(31, 138, 91, 0.18), transparent 34%),
    linear-gradient(140deg, #e9f2ed 0%, #f8faf7 45%, #dce9f7 100%);
  box-shadow: var(--shadow);
}

.desktop-logo {
  position: absolute;
  inset: 36px 0 auto;
  text-align: center;
  color: rgba(16, 20, 23, 0.22);
  font-size: clamp(44px, 8vw, 86px);
  font-weight: 900;
}

.window {
  position: absolute;
  left: 8%;
  right: 8%;
  top: 18%;
  min-height: 300px;
  border: 1px solid rgba(16, 20, 23, 0.14);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 22px 55px rgba(16, 20, 23, 0.18);
  backdrop-filter: blur(18px);
}

.window-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 14px;
  border-bottom: 1px solid var(--line);
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.red { background: #e15554; }
.yellow { background: #d99b28; }
.green { background: #35a66f; }

.window-bar strong {
  margin-left: 8px;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 14px;
  border-bottom: 1px solid var(--line);
}

.toolbar span {
  padding: 7px 10px;
  border-radius: 7px;
  background: #eef3ef;
  color: #384440;
  font-size: 13px;
  font-weight: 700;
}

.file-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  padding: 18px;
}

.file-tile {
  display: grid;
  justify-items: center;
  gap: 10px;
  min-width: 0;
  padding: 16px 8px;
  border: 1px solid #e3e9e4;
  border-radius: 8px;
  background: #fbfcfb;
}

.file-tile span {
  width: 46px;
  height: 42px;
  border-radius: 10px;
}

.file-tile b {
  max-width: 100%;
  overflow: hidden;
  font-size: 13px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.folder span { background: linear-gradient(#f3c45f 0 34%, #e0a72f 34%); }
.video span { background: linear-gradient(135deg, #2563eb, #7c3aed); }
.audio span { background: linear-gradient(135deg, #0f766e, #22c55e); }
.disk span { background: linear-gradient(135deg, #475569, #111827); }

.taskbar {
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 8px;
  border: 1px solid rgba(255, 255, 255, 0.65);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(18px);
}

.start {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--ink);
  color: white;
  font-weight: 900;
}

.task,
.status {
  padding: 8px 12px;
  border-radius: 8px;
  background: rgba(238, 243, 239, 0.92);
  font-size: 13px;
  font-weight: 800;
}

.status {
  margin-left: auto;
  color: var(--teal);
}

.intro {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1fr);
  gap: 34px;
  align-items: start;
  padding: 56px 0 28px;
}

.intro h2,
.band h2,
.faq h2 {
  margin-bottom: 0;
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1.15;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  padding: 22px 0 70px;
}

.feature-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
}

.feature-icon {
  display: block;
  width: 38px;
  height: 38px;
  margin-bottom: 20px;
  border-radius: 10px;
}

.feature-icon.storage { background: linear-gradient(135deg, var(--green), #6abf69); }
.feature-icon.desktop { background: linear-gradient(135deg, var(--blue), #60a5fa); }
.feature-icon.usb { background: linear-gradient(135deg, var(--amber), #f6ad55); }
.feature-icon.update { background: linear-gradient(135deg, #111827, #64748b); }

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

.feature-card p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.75;
}

.band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  margin-bottom: 72px;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  box-shadow: 0 18px 50px rgba(16, 20, 23, 0.08);
}

.page-hero {
  padding: 80px 0 34px;
}

.page-hero h1 {
  margin-bottom: 18px;
}

.guide-layout {
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
  gap: 22px;
  align-items: start;
  padding-bottom: 38px;
}

.guide-aside {
  position: sticky;
  top: 96px;
  display: grid;
  gap: 14px;
}

.mini-toc {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.86);
}

.mini-toc a {
  padding: 10px 12px;
  border-radius: 7px;
  color: var(--muted);
  font-weight: 800;
}

.mini-toc a:hover {
  background: #eef3ef;
  color: var(--ink);
}

.notice {
  padding: 22px;
  border: 1px solid #f1d09c;
  border-radius: 8px;
  background: #fff8eb;
}

.notice strong {
  display: block;
  margin-bottom: 8px;
}

.notice p {
  margin-bottom: 0;
  color: #75552b;
  line-height: 1.75;
}

.steps {
  display: grid;
  gap: 14px;
}

.step {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 18px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.9);
}

.step-num {
  color: var(--green);
  font-size: 26px;
  font-weight: 900;
}

.step h2 {
  margin-bottom: 10px;
  font-size: 24px;
}

.step p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.85;
}

.checklist {
  display: grid;
  gap: 8px;
  margin: 16px 0 0;
  padding-left: 20px;
  color: var(--muted);
  line-height: 1.75;
}

.image-row,
.image-grid {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.image-row {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.image-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

figure img {
  display: block;
  width: 100%;
  height: 210px;
  object-fit: contain;
  background: #f2f5f2;
}

figcaption {
  padding: 10px 12px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.wide-image {
  margin-top: 18px;
}

.wide-image img {
  height: auto;
  max-height: 560px;
}

.faq {
  padding: 12px 0 72px;
}

.faq h2 {
  margin-bottom: 18px;
}

details {
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.68);
}

details:last-child {
  border-bottom: 1px solid var(--line);
}

summary {
  cursor: pointer;
  padding: 18px 4px;
  font-weight: 800;
}

details p {
  margin: 0;
  padding: 0 4px 18px;
  color: var(--muted);
  line-height: 1.8;
}

.source-note {
  margin: 20px 0 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer {
  display: flex;
  justify-content: space-between;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 24px 0 38px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-weight: 700;
}

@media (max-width: 920px) {
  .hero,
  .intro,
  .guide-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 48px;
  }

  .desktop-preview {
    min-height: 460px;
  }

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .image-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .guide-aside {
    position: static;
  }
}

@media (max-width: 640px) {
  .site-header {
    width: calc(100% - 20px);
    margin-top: 10px;
  }

  .brand span:last-child {
    display: none;
  }

  .nav a {
    padding-inline: 9px;
  }

  .hero,
  .page-hero,
  .intro,
  .feature-grid,
  .band,
  .guide-layout,
  .faq,
  .footer {
    width: calc(100% - 20px);
  }

  h1 {
    font-size: 38px;
  }

  .hero-sub,
  .page-hero p,
  .intro p {
    font-size: 16px;
  }

  .hero-actions,
  .band,
  .footer {
    flex-direction: column;
    align-items: stretch;
  }

  .desktop-preview {
    min-height: 390px;
    border-radius: 12px;
  }

  .window {
    left: 4%;
    right: 4%;
    top: 20%;
  }

  .file-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .status {
    display: none;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .band {
    padding: 24px;
  }

  .step {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .image-row,
  .image-grid {
    grid-template-columns: 1fr;
  }

  figure img {
    height: auto;
    max-height: 360px;
  }
}