:root {
  --background: #07111f;
  --foreground: #f3fbff;
  --muted: #a9c4df;
  --line: rgba(117, 190, 255, 0.2);
  --accent: #53dbff;
  --accent-2: #7891ff;
  --accent-3: #42edcc;
  --panel: rgba(11, 29, 57, 0.86);
  --panel-strong: rgba(15, 39, 76, 0.92);
  --shadow: 0 30px 90px rgba(0, 7, 20, 0.46);
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--foreground);
  background:
    radial-gradient(circle at 15% 10%, rgba(83, 219, 255, 0.2), transparent 24%),
    radial-gradient(circle at 86% 8%, rgba(120, 145, 255, 0.18), transparent 26%),
    radial-gradient(circle at 50% 100%, rgba(66, 237, 204, 0.08), transparent 30%),
    linear-gradient(180deg, #081224 0%, #0b1a34 45%, #07101d 100%);
  font-family: Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  overflow-x: hidden;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  content: "";
  background-image:
    linear-gradient(rgba(117, 190, 255, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(117, 190, 255, 0.08) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(180deg, #000 8%, transparent 96%);
  opacity: 0.7;
}

a {
  color: inherit;
}

.page-shell {
  width: min(1440px, calc(100% - 32px));
  margin: 0 auto;
  padding: 16px 0 34px;
}

.brand-header {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  min-height: 136px;
  margin-bottom: 14px;
  padding: 24px;
  overflow: hidden;
  border: 1px solid rgba(104, 190, 255, 0.2);
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(18, 47, 92, 0.96), rgba(8, 22, 43, 0.94)),
    radial-gradient(circle at 12% 16%, rgba(83, 219, 255, 0.24), transparent 24%);
  box-shadow: var(--shadow);
}

.language-switch {
  position: absolute;
  top: 18px;
  right: 18px;
  z-index: 2;
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  border: 1px solid rgba(83, 219, 255, 0.24);
  border-radius: 999px;
  background: rgba(5, 15, 31, 0.72);
}

.lang-button {
  min-width: 54px;
  min-height: 32px;
  padding: 6px 10px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: #c2d9ef;
  font: inherit;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.02em;
  cursor: pointer;
}

.lang-button.is-active {
  background: linear-gradient(135deg, rgba(83, 219, 255, 0.26), rgba(66, 237, 204, 0.2));
  color: #f3fbff;
  box-shadow: 0 0 18px rgba(83, 219, 255, 0.22);
}

.lang-button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.brand-header::after {
  position: absolute;
  inset: 0;
  content: "";
  background:
    radial-gradient(circle at 12% 22%, rgba(83, 219, 255, 0.18), transparent 20%),
    linear-gradient(135deg, rgba(255, 255, 255, 0.06), transparent 35%, transparent 68%, rgba(83, 219, 255, 0.08));
  pointer-events: none;
}

.brand-copy {
  position: relative;
  z-index: 1;
  text-align: center;
}

.brand-copy h1 {
  max-width: 820px;
  margin: 0;
  color: #f5fbff;
  font-size: clamp(30px, 4vw, 54px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: 0.06em;
  text-shadow: 0 0 24px rgba(83, 219, 255, 0.18);
}

.product-section {
  margin-bottom: 14px;
}

.product-card {
  position: relative;
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(360px, 1.28fr);
  gap: 20px;
  align-items: center;
  padding: 18px;
  overflow: hidden;
  border: 1px solid rgba(104, 190, 255, 0.22);
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(15, 40, 79, 0.94), rgba(8, 21, 41, 0.96)),
    radial-gradient(circle at 10% 16%, rgba(255, 210, 58, 0.14), transparent 26%),
    radial-gradient(circle at 88% 30%, rgba(83, 219, 255, 0.16), transparent 24%);
  box-shadow: var(--shadow);
}

.product-card::after {
  position: absolute;
  inset: 0;
  content: "";
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), transparent 38%, rgba(83, 219, 255, 0.08));
  pointer-events: none;
}

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

.product-image-frame {
  width: min(100%, 430px);
  justify-self: center;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid rgba(104, 190, 255, 0.2);
  border-radius: 18px;
  background: #f8fbff;
  box-shadow: 0 20px 48px rgba(0, 7, 20, 0.32);
}

.product-image-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

.product-copy {
  display: grid;
  gap: 10px;
  align-content: center;
}

.product-eyebrow {
  width: fit-content;
  padding: 8px 12px;
  border: 1px solid rgba(83, 219, 255, 0.28);
  border-radius: 999px;
  background: rgba(83, 219, 255, 0.12);
  color: #dff8ff;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.product-copy h2 {
  margin: 0;
  color: #f5fbff;
  font-size: clamp(28px, 3vw, 44px);
  line-height: 1.15;
  letter-spacing: 0.03em;
}

.product-copy p {
  margin: 0;
  color: #c2d9ef;
  font-size: 15px;
  line-height: 1.72;
}

.product-highlight {
  padding: 13px 15px;
  border: 1px solid rgba(255, 214, 82, 0.28);
  border-radius: 16px;
  background: rgba(255, 214, 82, 0.1);
  color: #fff2bd !important;
}

.hero-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 14px;
}

.panel {
  position: relative;
  min-height: 640px;
  padding: 16px;
  overflow: hidden;
  border: 1px solid rgba(96, 171, 239, 0.22);
  border-radius: 28px;
  background: linear-gradient(180deg, var(--panel-strong), rgba(8, 21, 41, 0.96));
  box-shadow: var(--shadow);
}

.panel::after {
  position: absolute;
  inset: 0;
  content: "";
  background:
    linear-gradient(135deg, rgba(83, 219, 255, 0.13), transparent 32%, transparent 72%, rgba(120, 145, 255, 0.11)),
    radial-gradient(circle at 18% 18%, rgba(83, 219, 255, 0.08), transparent 20%);
  mix-blend-mode: screen;
  pointer-events: none;
}

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

.section-label {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.section-label span {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  box-shadow: 0 0 18px rgba(83, 219, 255, 0.9);
}

.section-label h2 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.08em;
}

.download-panel,
.manual-panel,
.tutorial-panel {
  display: grid;
  gap: 16px;
}

.download-panel {
  grid-template-rows: auto auto auto 1fr;
}

.manual-panel {
  grid-template-rows: auto auto 1fr;
}

.tutorial-panel {
  grid-template-rows: auto 1fr;
}

.folder-card {
  position: relative;
  min-height: 228px;
  padding-top: 32px;
  overflow: hidden;
  border-radius: 22px 22px 20px 20px;
  color: #06152b;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.24);
}

.folder-card::before {
  position: absolute;
  top: 0;
  left: 18px;
  width: 108px;
  height: 34px;
  border-radius: 14px 14px 0 0;
  content: "";
  background: linear-gradient(180deg, rgba(235, 250, 255, 1), rgba(158, 225, 255, 1));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.34);
}

.folder-card::after {
  position: absolute;
  inset: 0;
  content: "";
  background:
    radial-gradient(circle at 20% 16%, rgba(255, 255, 255, 0.2), transparent 22%),
    linear-gradient(135deg, rgba(255, 255, 255, 0.16), transparent 34%, transparent 72%, rgba(12, 58, 130, 0.14));
  pointer-events: none;
}

.folder-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.folder-card.windows {
  background: linear-gradient(180deg, #77d1ff, #2b78ee);
}

.folder-card.mac {
  background: linear-gradient(180deg, #7affc8, #5b6cff);
}

.folder-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 196px;
  padding: 20px;
}

.folder-tag {
  width: fit-content;
  margin-bottom: 12px;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.22);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.folder-card h3 {
  max-width: 320px;
  margin: 0 0 8px;
  font-size: 28px;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.04em;
}

.folder-card a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 184px;
  height: 66px;
  margin-top: 16px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 18px;
  background: rgba(7, 23, 48, 0.28);
  color: #06152b;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.folder-card a:hover {
  transform: translateY(-2px);
  background: rgba(7, 23, 48, 0.36);
  box-shadow: 0 14px 28px rgba(3, 10, 25, 0.2);
}

.folder-card svg {
  width: 34px;
  height: 34px;
  fill: currentColor;
}

.manual-list,
.manual-download-block {
  display: grid;
  gap: 14px;
}

.manual-download-block {
  align-self: start;
}

.manual-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: 82px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(83, 219, 255, 0.1), rgba(120, 145, 255, 0.14));
  text-decoration: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}

.manual-link:hover {
  transform: translateY(-2px);
  border-color: rgba(83, 219, 255, 0.42);
  box-shadow: 0 12px 28px rgba(83, 219, 255, 0.18);
}

.manual-link strong {
  display: block;
  color: #f3fbff;
  font-size: 16px;
  line-height: 1.4;
  letter-spacing: 0.02em;
}

.manual-link small {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: 13px;
}

.manual-link .arrow {
  flex: 0 0 auto;
  color: var(--accent);
  font-size: 22px;
  line-height: 1;
}

.tutorial-block {
  display: grid;
  gap: 0;
  align-self: end;
  margin-top: 0;
}

.video-card,
.contact-card {
  border: 1px solid var(--line);
  border-radius: 20px;
  background: linear-gradient(180deg, rgba(14, 39, 78, 0.9), rgba(9, 23, 45, 0.92));
  padding: 20px;
}

.video-card {
  display: grid;
  align-content: center;
  min-height: 100%;
  padding: 14px;
}

.video-frame {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 16px;
  background:
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px) 0 0 / 18px 18px,
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px) 0 0 / 18px 18px,
    rgba(3, 10, 25, 0.5);
  box-shadow: 0 18px 40px rgba(3, 10, 25, 0.26);
}

.tutorial-panel .video-frame {
  width: min(100%, 390px);
  height: min(68vh, 620px);
  min-height: 500px;
  margin: 0 auto;
  aspect-ratio: 9 / 16;
  border-radius: 28px;
}

.video-frame.placeholder span,
.video-frame.phone-placeholder span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 160px;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid rgba(83, 219, 255, 0.28);
  border-radius: 999px;
  background: rgba(83, 219, 255, 0.1);
  color: #dff8ff;
  font-size: 14px;
  letter-spacing: 0.06em;
}

.video-card h3,
.contact-card h3 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.04em;
}

.video-card h3 {
  margin-top: 14px;
}

.video-frame video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.contact-card {
  display: grid;
  justify-items: center;
  gap: 8px;
  text-align: center;
}

.download-contact {
  align-self: end;
  justify-self: stretch;
  padding: 12px;
}

.contact-card strong {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 32px;
  padding: 6px 12px;
  border: 1px solid rgba(83, 219, 255, 0.24);
  border-radius: 999px;
  background: rgba(83, 219, 255, 0.12);
  color: #f3fbff;
  font-size: 15px;
  letter-spacing: 0.04em;
}

.contact-card img {
  display: block;
  width: min(100%, 280px);
  height: auto;
  border: 1px solid rgba(104, 190, 255, 0.24);
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 18px 40px rgba(3, 10, 25, 0.28);
}

.download-contact img {
  width: min(100%, 132px);
}

@media (max-width: 1180px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .panel {
    min-height: auto;
  }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(100% - 20px, 100%);
    padding-top: 12px;
  }

  .brand-header {
    align-items: flex-start;
    flex-direction: column;
    min-height: auto;
    padding: 22px;
    border-radius: 22px;
  }

  .language-switch {
    position: relative;
    top: auto;
    right: auto;
    align-self: flex-end;
    margin-bottom: 6px;
  }

  .brand-copy h1 {
    font-size: 30px;
    letter-spacing: 0.03em;
  }

  .product-card {
    grid-template-columns: 1fr;
    padding: 14px;
    border-radius: 22px;
  }

  .product-image-frame {
    width: 100%;
    max-width: 420px;
  }

  .product-copy h2 {
    font-size: 28px;
  }

  .panel {
    padding: 14px;
    border-radius: 22px;
  }

  .folder-card {
    min-height: 220px;
  }

  .folder-card h3 {
    font-size: 24px;
  }

  .folder-card a {
    width: 156px;
  }

  .manual-link {
    align-items: flex-start;
  }

  .tutorial-panel .video-frame {
    width: min(100%, 330px);
    min-height: 480px;
    height: auto;
  }
}