:root {
  color-scheme: dark;
  --bg-start: #020617;
  --bg-mid: #0f172a;
  --bg-end: #111827;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --card-bg: rgba(15, 23, 42, 0.75);
  --border: rgba(148, 163, 184, 0.2);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-main);
  background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.18), transparent 30%),
    linear-gradient(135deg, var(--bg-start), var(--bg-mid), var(--bg-end));
  overflow: hidden;
  position: relative;
}

body::before,
body::after {
  content: "";
  position: absolute;
  inset: auto;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.24;
  animation: drift 8s ease-in-out infinite alternate;
}

body::before {
  background: #38bdf8;
  top: -80px;
  left: -80px;
}

body::after {
  background: #8b5cf6;
  right: -100px;
  bottom: -100px;
  animation-delay: 2s;
}

.hero {
  width: min(100%, 820px);
  position: relative;
  z-index: 1;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 28px;
  padding: 42px 32px;
  box-shadow: 0 20px 60px rgba(2, 6, 23, 0.45), inset 0 1px 0 rgba(255, 255, 255, 0.07);
  text-align: center;
  backdrop-filter: blur(18px);
  animation: riseIn 0.7s ease both;
}

.brand {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 18px;
}

.brand-mark {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.24), rgba(249, 115, 22, 0.24));
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 18px;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.04), 0 0 26px rgba(56, 189, 248, 0.2);
  animation: float 1s ease-in-out infinite;
  transform-origin: center;
  will-change: transform;
  transform: translateZ(0);
}

.brand-mark img,
.brand-mark svg {
  width: 36px;
  height: 36px;
  display: block;
  transform: translateZ(0);
}

.brand-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.brand-name {
  font-size: 1.2rem;
  font-weight: 700;
}

.brand-subtitle {
  font-size: 0.9rem;
  color: var(--text-muted);
}

h1 {
  margin: 0 0 10px;
  font-size: 2rem;
  font-weight: 700;
}

p {
  margin: 0;
  font-size: 1rem;
  color: var(--text-muted);
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 30px;
}

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-width: 180px;
  padding: 15px 22px;
  border-radius: 16px;
  text-decoration: none;
  color: #ffffff;
  font-weight: 700;
  letter-spacing: 0.01em;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 12px 24px rgba(2, 6, 23, 0.28);
  transition: transform 0.18s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: transform, box-shadow;
  transform: translateZ(0);
  backface-visibility: hidden;
  overflow: hidden;
}

.btn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent, rgba(255, 255, 255, 0.16), transparent);
  transform: translateX(-120%) translateZ(0);
  transition: transform 0.35s ease;
  will-change: transform;
}

.btn:hover {
  transform: translate3d(0, -3px, 0);
  box-shadow: 0 16px 32px rgba(2, 6, 23, 0.35);
}

.btn:hover::before {
  transform: translateX(120%) translateZ(0);
}

.btn-windows {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
}

.btn-mac {
  background: linear-gradient(135deg, #111827, #374151);
}

.btn-linux {
  background: linear-gradient(135deg, #16a34a, #15803d);
}

.icon,
.icon-img {
  width: 24px;
  height: 24px;
  min-width: 24px;
  min-height: 24px;
  object-fit: contain;
  transition: transform 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: transform;
  transform: translateZ(0);
}

.btn:hover .icon-img {
  transform: translate3d(0, -1px, 0) scale(1.02);
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes drift {
  from {
    transform: translate(0, 0) scale(1);
  }
  to {
    transform: translate(30px, -40px) scale(1.08);
  }
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.04);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translate3d(0, 0, 0) scale(1);
  }
  25% {
    transform: translate3d(0, -3px, 0) scale(1.01);
  }
  50% {
    transform: translate3d(0, -6px, 0) scale(1.02);
  }
  75% {
    transform: translate3d(0, -3px, 0) scale(1.01);
  }
}

@media (max-width: 600px) {
  .card {
    padding: 32px 20px;
  }

  .btn {
    width: 100%;
  }
}