:root {
  --primary: #13C2C2;
  --primary-dark: #0CAFB0;
  --primary-light: #26E2D6;
  --primary-soft: #E6F9F8;
  --text: #1A2B2B;
  --text-secondary: #5C6F6F;
  --muted: #9AABB0;
  --bg: #f7fbfb;
  --page: #eef5f5;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-strong: rgba(255, 255, 255, 0.88);
  --shadow: 0 18px 50px rgba(12, 90, 92, 0.08);
}

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

html {
  overflow-x: hidden;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  color: var(--text);
  font-family: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  background:
    radial-gradient(120% 80% at 50% -10%, #d8f6f4 0%, transparent 55%),
    linear-gradient(165deg, #eaf7f6 0%, #f7fbfb 42%, #eef4f4 100%);
}

/* —— Atmosphere layers —— */
.atmosphere {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.atmosphere__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.55;
  will-change: transform;
}

.atmosphere__glow--a {
  width: min(72vw, 560px);
  height: min(72vw, 560px);
  top: -12%;
  left: 50%;
  transform: translateX(-50%);
  background: radial-gradient(circle, rgba(38, 226, 214, 0.55) 0%, rgba(19, 194, 194, 0.18) 45%, transparent 70%);
  animation: drift-a 18s ease-in-out infinite alternate;
}

.atmosphere__glow--b {
  width: min(50vw, 380px);
  height: min(50vw, 380px);
  bottom: 8%;
  left: -8%;
  background: radial-gradient(circle, rgba(12, 175, 176, 0.28) 0%, transparent 68%);
  animation: drift-b 22s ease-in-out infinite alternate;
}

.atmosphere__glow--c {
  width: min(46vw, 340px);
  height: min(46vw, 340px);
  top: 38%;
  right: -10%;
  background: radial-gradient(circle, rgba(19, 194, 194, 0.22) 0%, transparent 70%);
  animation: drift-c 20s ease-in-out infinite alternate;
}

.atmosphere__mesh {
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image:
    linear-gradient(rgba(19, 194, 194, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(19, 194, 194, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, #000 20%, transparent 75%);
}

@keyframes drift-a {
  from { transform: translateX(-50%) translateY(0); }
  to { transform: translateX(-46%) translateY(18px); }
}

@keyframes drift-b {
  from { transform: translate(0, 0); }
  to { transform: translate(24px, -16px); }
}

@keyframes drift-c {
  from { transform: translate(0, 0); }
  to { transform: translate(-20px, 22px); }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .atmosphere__glow {
    animation: none;
  }

  .hero > * {
    animation: none !important;
  }
}

/* —— Hero —— */
.hero {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(3.25rem, 10vh, 5.5rem) 1.25rem 4rem;
  text-align: center;
}

.hero > * {
  animation: rise-in 0.7s ease both;
}

.hero > .brand-logo { animation-delay: 0.02s; }
.hero > .brand-domain { animation-delay: 0.08s; }
.hero > .brand-name { animation-delay: 0.14s; }
.hero > .brand-en { animation-delay: 0.2s; }
.hero > .tagline { animation-delay: 0.26s; }
.hero > .platform-grid { animation-delay: 0.34s; }
.hero > .android-status { animation-delay: 0.38s; }
.hero > .features { animation-delay: 0.44s; }

.brand-logo {
  display: block;
  width: 88px;
  height: 88px;
  margin: 0 auto 1.15rem;
  border-radius: 22px;
  object-fit: cover;
  box-shadow:
    0 16px 36px rgba(12, 175, 176, 0.28),
    0 2px 0 rgba(255, 255, 255, 0.55) inset;
}

.brand-domain {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: lowercase;
  color: var(--primary-dark);
  margin-bottom: 0.85rem;
}

@media (min-width: 768px) {
  .brand-logo {
    width: 104px;
    height: 104px;
    border-radius: 26px;
    margin-bottom: 1.35rem;
  }
}

.brand-name {
  margin: 0;
  font-size: clamp(2.75rem, 9vw, 4rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: 0.12em;
  background: linear-gradient(135deg, #0a8f90 0%, #13C2C2 45%, #1ad4c8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: none;
}

.brand-en {
  margin-top: 0.55rem;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.34em;
  text-indent: 0.34em;
  color: var(--text-secondary);
}

.tagline {
  margin: 1.35rem auto 2.35rem;
  max-width: 22em;
  font-size: 1.0625rem;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.8rem;
  margin-bottom: 1rem;
}

@media (min-width: 768px) {
  .platform-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.95rem;
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0.8rem 1rem;
  border-radius: 14px;
  border: 1.5px solid transparent;
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  color: #fff;
  background: linear-gradient(145deg, var(--primary-light), var(--primary-dark));
  box-shadow: 0 10px 24px rgba(12, 175, 176, 0.22);
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, border-color 0.18s ease, color 0.18s ease;
  cursor: pointer;
  user-select: none;
  backdrop-filter: blur(8px);
}

.btn:hover:not(.btn-disabled):not([aria-disabled="true"]) {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px rgba(12, 175, 176, 0.28);
}

.btn:active:not(.btn-disabled):not([aria-disabled="true"]) {
  transform: translateY(0);
}

.btn-outline {
  color: var(--primary-dark);
  background: var(--surface-strong);
  border-color: rgba(19, 194, 194, 0.45);
  box-shadow: var(--shadow);
}

.btn-outline:hover:not(.btn-disabled):not([aria-disabled="true"]) {
  background: #fff;
  border-color: var(--primary);
  color: var(--primary-dark);
}

.btn-disabled,
.btn[aria-disabled="true"] {
  color: var(--muted);
  background: var(--surface);
  border-color: rgba(154, 171, 176, 0.25);
  box-shadow: none;
  cursor: not-allowed;
  pointer-events: none;
}

.android-status {
  margin: 0 0 1.5rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.android-status[hidden] {
  display: none;
}

.features {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
  margin: 2.4rem 0 0;
  padding: 0;
  list-style: none;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  letter-spacing: 0.04em;
}

.features li {
  position: relative;
  padding: 0;
  background: none;
  border: none;
  border-radius: 0;
}

.features li::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 0.55rem;
  border-radius: 50%;
  background: var(--primary);
  vertical-align: 0.15em;
  opacity: 0.85;
}

@media (min-width: 768px) {
  .features {
    flex-direction: row;
    justify-content: center;
    gap: 1.75rem;
  }
}