:root {
  --bg: #050508;
  --text: #f5f6fa;
  --muted: #8e8ea0;
  --line: rgba(255, 255, 255, 0.08);
  --cyan: #4ee3f5;
  --violet: #c86bff;
  --card: rgba(255, 255, 255, 0.035);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  min-height: 100%;
}

body {
  font-family: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

.bg {
  position: fixed;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.glow {
  position: absolute;
  width: 42vw;
  height: 42vw;
  min-width: 280px;
  min-height: 280px;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.28;
}

.glow-a {
  top: -12%;
  left: -8%;
  background: #3a1b6e;
}

.glow-b {
  right: -10%;
  bottom: 18%;
  background: #123a68;
}

.page {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: calc(28px + var(--safe-top)) 24px calc(36px + var(--safe-bottom));
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  letter-spacing: 0.28em;
  font-size: 11px;
  color: var(--muted);
}

.brand-mark {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  box-shadow: 0 0 10px rgba(78, 227, 245, 0.55);
}

.brand-text {
  font-family: Syne, "Noto Sans SC", sans-serif;
  font-weight: 700;
}

.hero {
  width: 100%;
  max-width: 560px;
  margin: 0 auto;
  padding: 48px 0 8px;
  text-align: center;
}

.icon-wrap {
  position: relative;
  width: 112px;
  height: 112px;
  margin: 0 auto 28px;
}

.icon-ring {
  position: absolute;
  inset: -10px;
  border-radius: 32px;
  background: linear-gradient(135deg, rgba(78, 227, 245, 0.45), rgba(200, 107, 255, 0.45));
  filter: blur(14px);
  opacity: 0.7;
}

.icon {
  position: relative;
  width: 112px;
  height: 112px;
  border-radius: 26px;
  display: block;
  background: #000;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
}

.title {
  font-family: Syne, "Noto Sans SC", sans-serif;
  font-size: 40px;
  font-weight: 800;
  letter-spacing: 0.02em;
  line-height: 1.1;
}

.tagline {
  margin-top: 12px;
  font-size: 16px;
  color: #d7d7e4;
  letter-spacing: 0.06em;
}

.lead {
  margin: 16px auto 0;
  max-width: 460px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.meta {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 22px;
  font-size: 13px;
  color: #c9c9d6;
}

.dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: #5c5c6e;
}

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 320px;
  height: 54px;
  margin: 32px auto 0;
  border-radius: 999px;
  background: linear-gradient(135deg, #4ee3f5 0%, #7a7bff 52%, #c86bff 100%);
  color: #071018;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.04em;
  box-shadow: 0 12px 32px rgba(122, 123, 255, 0.28);
  transition: transform 0.18s ease, opacity 0.18s ease, filter 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
  filter: brightness(1.05);
}

.btn:active {
  transform: translateY(0);
}

.btn[aria-disabled="true"] {
  opacity: 0.48;
  pointer-events: none;
  box-shadow: none;
}

.hint,
.error {
  margin-top: 14px;
  font-size: 12px;
  color: var(--muted);
}

.error {
  color: #ff8b8b;
}

.retry {
  margin-top: 16px;
  border: 1px solid var(--line);
  background: transparent;
  color: #d7d7e4;
  font: inherit;
  font-size: 13px;
  padding: 8px 16px;
  border-radius: 999px;
  cursor: pointer;
}

.block {
  width: 100%;
  max-width: 880px;
  margin-top: 56px;
}

.block-title {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--muted);
  margin-bottom: 16px;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.feature {
  padding: 20px 18px 18px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--card);
}

.feature-icon {
  width: 36px;
  height: 36px;
  margin-bottom: 14px;
  color: #c9b8ff;
}

.feature-icon svg {
  width: 100%;
  height: 100%;
}

.feature h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature p {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

.split {
  display: grid;
  gap: 12px;
}

.panel {
  padding: 22px 20px 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--card);
}

.panel-text {
  font-size: 14px;
  line-height: 1.8;
  color: #d0d0dc;
}

.panel-text + .panel-text {
  margin-top: 10px;
}

.steps {
  margin-left: 18px;
  font-size: 14px;
  line-height: 1.9;
  color: #d0d0dc;
}

.notes {
  width: 100%;
  max-width: 880px;
  margin-top: 24px;
  padding: 22px 22px 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--card);
  text-align: left;
}

.notes h2 {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 10px;
}

.notes p {
  font-size: 14px;
  line-height: 1.75;
  color: #d8d8e4;
  white-space: pre-wrap;
}

.foot {
  margin-top: auto;
  padding-top: 56px;
  text-align: center;
  color: #6d6d7c;
  font-size: 12px;
  line-height: 1.8;
}

.mask {
  position: fixed;
  inset: 0;
  z-index: 20;
  background: rgba(5, 5, 8, 0.72);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: flex-start;
  justify-content: flex-end;
  padding: 18px 18px 0;
}

.mask[hidden],
.notes[hidden],
.error[hidden],
.retry[hidden],
.meta[hidden],
#metaSize[hidden],
#sizeDot[hidden] {
  display: none !important;
}

.mask-card {
  width: min(280px, 86vw);
  padding: 22px 20px 18px;
  border-radius: 16px;
  background: #16161e;
  border: 1px solid var(--line);
  text-align: center;
}

.mask-arrow {
  text-align: right;
  font-size: 28px;
  line-height: 1;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.mask-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.mask-desc {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
}

.mask-close {
  margin-top: 16px;
  width: 100%;
  height: 40px;
  border: 0;
  border-radius: 999px;
  background: linear-gradient(135deg, #4ee3f5, #c86bff);
  color: #071018;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

@media (min-width: 720px) {
  .hero {
    padding-top: 64px;
  }

  .title {
    font-size: 48px;
  }

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

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

@media (min-width: 980px) {
  .feature-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
}