:root {
  --bg0: #0b1220;
  --bg1: #152238;
  --accent: #ff5a7a;
  --accent2: #ff8f5a;
  --text: #f5f7fb;
  --muted: #a7b0c0;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  font-family: "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg0);
}

.bg {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(1200px 600px at 20% -10%, rgba(255, 90, 122, 0.35), transparent 60%),
    radial-gradient(900px 500px at 100% 10%, rgba(255, 143, 90, 0.25), transparent 55%),
    linear-gradient(160deg, var(--bg0), var(--bg1));
  z-index: 0;
}

.card {
  position: relative;
  z-index: 1;
  max-width: 420px;
  margin: 0 auto;
  padding: 72px 28px 48px;
  text-align: center;
}

.logo {
  width: 88px;
  height: 88px;
  margin: 0 auto 20px;
  border-radius: 22px;
  display: grid;
  place-items: center;
  font-size: 36px;
  font-weight: 700;
  background: linear-gradient(145deg, var(--accent), var(--accent2));
  box-shadow: 0 16px 40px rgba(255, 90, 122, 0.35);
}

h1 {
  margin: 0 0 10px;
  font-size: 28px;
  letter-spacing: 0.02em;
}

.tagline {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.5;
}

.channel {
  margin: -12px 0 24px;
  color: #8fd3ff;
  font-size: 13px;
}

.btn {
  display: block;
  width: 100%;
  padding: 16px 20px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  text-decoration: none;
  font-size: 17px;
  font-weight: 600;
  box-shadow: 0 12px 28px rgba(255, 90, 122, 0.35);
}

.btn:active {
  transform: scale(0.98);
}

.hint,
.foot {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}