:root {
  --ink: #06262c;
  --ink-soft: #143a42;
  --mint: #1fa87a;
  --mint-bright: #2dd4a0;
  --sand: #e8f3ef;
  --paper: #f4faf7;
  --white: #ffffff;
  --line: rgba(6, 38, 44, 0.12);
  --shadow: 0 24px 60px rgba(6, 38, 44, 0.18);
  --font-display: "Syne", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100%;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(45, 212, 160, 0.18), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(15, 90, 110, 0.16), transparent 50%),
    linear-gradient(180deg, #eef8f4 0%, var(--paper) 38%, #ffffff 100%);
  line-height: 1.65;
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px clamp(18px, 4vw, 48px);
  backdrop-filter: blur(14px);
  background: rgba(244, 250, 247, 0.78);
  border-bottom: 1px solid rgba(6, 38, 44, 0.06);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-mark__glyph {
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background:
    linear-gradient(145deg, var(--mint-bright), #0f5a6e);
  box-shadow: 0 8px 18px rgba(31, 168, 122, 0.35);
  animation: pulse-mark 3.6s ease-in-out infinite;
}

.brand-mark__text {
  font-size: 1.05rem;
}

.topbar__nav {
  display: flex;
  gap: clamp(14px, 3vw, 28px);
  font-size: 0.95rem;
  font-weight: 500;
}

.topbar__nav a {
  position: relative;
  opacity: 0.78;
  transition: opacity 0.2s ease;
}

.topbar__nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 100%;
  height: 2px;
  background: var(--mint);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}

.topbar__nav a:hover,
.topbar__nav a:focus-visible {
  opacity: 1;
}

.topbar__nav a:hover::after,
.topbar__nav a:focus-visible::after {
  transform: scaleX(1);
}

.hero {
  position: relative;
  min-height: min(100vh, 860px);
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: clamp(24px, 5vw, 56px);
  padding: clamp(40px, 8vh, 88px) clamp(18px, 4vw, 48px) clamp(48px, 8vh, 96px);
  overflow: hidden;
  color: var(--white);
  background:
    linear-gradient(135deg, #07343c 0%, #0b4d4f 42%, #12635a 100%);
}

.hero__atmosphere {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(8px);
  opacity: 0.55;
  animation: drift 14s ease-in-out infinite;
}

.hero__orb--a {
  width: 340px;
  height: 340px;
  left: -80px;
  top: -60px;
  background: radial-gradient(circle, rgba(45, 212, 160, 0.55), transparent 70%);
}

.hero__orb--b {
  width: 280px;
  height: 280px;
  right: 8%;
  bottom: -40px;
  background: radial-gradient(circle, rgba(120, 210, 255, 0.28), transparent 70%);
  animation-delay: -4s;
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 85%);
}

.hero__content,
.hero__visual {
  position: relative;
  z-index: 1;
}

.hero__brand {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.4vw, 2.35rem);
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 1.25;
}

.hero__title {
  margin: 0 0 16px;
  max-width: 12em;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.8vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
}

.hero__lead {
  margin: 0 0 28px;
  max-width: 34em;
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.84);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 600;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-1px);
}

.btn--primary {
  background: var(--mint-bright);
  color: var(--ink);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: #54e0b2;
}

.btn--ghost {
  border: 1px solid rgba(255, 255, 255, 0.42);
  color: var(--white);
  background: rgba(255, 255, 255, 0.06);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: rgba(255, 255, 255, 0.8);
  background: rgba(255, 255, 255, 0.12);
}

.hero__visual {
  display: flex;
  justify-content: center;
}

.hero-stage {
  position: relative;
  width: min(100%, 420px);
  height: 420px;
  filter: drop-shadow(var(--shadow));
}

.hero-phone {
  position: absolute;
  width: 230px;
  border-radius: 28px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background:
    linear-gradient(165deg, rgba(255, 255, 255, 0.16), rgba(255, 255, 255, 0.05));
  backdrop-filter: blur(10px);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.28);
  overflow: hidden;
}

.hero-phone--back {
  left: 0;
  top: 48px;
  transform: rotate(-8deg);
  opacity: 0.88;
  animation: phone-float 5.5s ease-in-out infinite;
}

.hero-phone--front {
  right: 0;
  top: 18px;
  transform: rotate(4deg);
  z-index: 2;
  animation: phone-float 5.5s ease-in-out infinite;
  animation-delay: -2.2s;
}

.hero-phone__bar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 14px 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.hero-phone__bar strong {
  display: block;
  font-size: 0.92rem;
  line-height: 1.2;
}

.hero-phone__bar small {
  display: block;
  margin-top: 2px;
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.72rem;
}

.hero-phone__avatar {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: #07343c;
  background: linear-gradient(145deg, #9ae6d0, #2dd4a0);
}

.hero-phone__avatar--mint {
  background: linear-gradient(145deg, #ffe08a, #2dd4a0);
}

.hero-phone__tag {
  margin-left: auto;
  padding: 3px 8px;
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #07343c;
  background: rgba(45, 212, 160, 0.92);
}

.hero-phone__chat {
  display: grid;
  gap: 8px;
  padding: 12px 12px 16px;
  min-height: 220px;
}

.bubble {
  max-width: 88%;
  padding: 9px 11px;
  border-radius: 14px;
  font-size: 0.78rem;
  line-height: 1.45;
  color: rgba(255, 255, 255, 0.92);
  animation: bubble-in 0.55s ease both;
}

.bubble--in {
  justify-self: start;
  background: rgba(255, 255, 255, 0.12);
  border-bottom-left-radius: 5px;
}

.bubble--out {
  justify-self: end;
  background: linear-gradient(135deg, rgba(45, 212, 160, 0.85), rgba(20, 140, 110, 0.9));
  border-bottom-right-radius: 5px;
}

.hero-phone--front .bubble:nth-child(1) { animation-delay: 0.35s; }
.hero-phone--front .bubble:nth-child(2) { animation-delay: 0.55s; }
.hero-phone--front .bubble:nth-child(3) { animation-delay: 0.75s; }
.hero-phone--front .bubble:nth-child(4) { animation-delay: 0.95s; }
.hero-phone--back .bubble:nth-child(1) { animation-delay: 0.45s; }
.hero-phone--back .bubble:nth-child(2) { animation-delay: 0.65s; }
.hero-phone--back .bubble:nth-child(3) { animation-delay: 0.85s; }

.bubble--typing {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  width: fit-content;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.12);
  border-bottom-left-radius: 5px;
}

.bubble--typing i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.75);
  animation: typing 1.1s ease-in-out infinite;
}

.bubble--typing i:nth-child(2) { animation-delay: 0.15s; }
.bubble--typing i:nth-child(3) { animation-delay: 0.3s; }

.hero-float {
  position: absolute;
  z-index: 3;
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
  color: #07343c;
  background: rgba(244, 250, 247, 0.92);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.18);
  animation: chip-float 4.8s ease-in-out infinite;
}

.hero-float--a {
  left: 18px;
  bottom: 58px;
}

.hero-float--b {
  right: 12px;
  bottom: 96px;
  animation-delay: -1.4s;
}

.hero-float--c {
  left: 46%;
  bottom: 28px;
  transform: translateX(-50%);
  animation-delay: -2.6s;
}

.section {
  padding: clamp(64px, 10vh, 110px) clamp(18px, 4vw, 48px);
}

.section__inner {
  max-width: 920px;
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--mint);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.section h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  line-height: 1.25;
}

.section__text {
  margin: 0;
  max-width: 40em;
  color: var(--ink-soft);
  font-size: 1.05rem;
}

.section--about {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.55), rgba(232, 243, 239, 0.9));
}

.section--product {
  background:
    radial-gradient(700px 280px at 0% 0%, rgba(31, 168, 122, 0.12), transparent 60%),
    #ffffff;
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.feature-list--ai {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.feature-list li {
  display: grid;
  gap: 8px;
  padding: 18px 16px;
  border-top: 2px solid var(--mint);
  background: linear-gradient(180deg, rgba(31, 168, 122, 0.08), transparent);
  font-weight: 600;
}

.feature-list li span {
  font-weight: 400;
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.55;
}

.section--contact {
  background:
    linear-gradient(160deg, #f0faf6 0%, #e7f4ef 45%, #ffffff 100%);
}

.contact-list {
  display: grid;
  gap: 18px;
  margin: 28px 0 0;
}

.contact-list div {
  display: grid;
  gap: 4px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.contact-list dt {
  font-size: 0.82rem;
  color: rgba(6, 38, 44, 0.55);
  letter-spacing: 0.04em;
}

.contact-list dd {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
}

.contact-list a {
  color: #0f6d55;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.contact-note {
  margin: 18px 0 0;
  font-size: 0.88rem;
  color: rgba(6, 38, 44, 0.55);
}

.footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding: 28px clamp(18px, 4vw, 48px) 40px;
  border-top: 1px solid var(--line);
  color: rgba(6, 38, 44, 0.62);
  font-size: 0.9rem;
}

.footer__links {
  display: flex;
  gap: 18px;
  margin: 0;
}

.footer__links a:hover,
.footer__links a:focus-visible {
  color: var(--ink);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.8s ease forwards;
}

.reveal--delay-1 { animation-delay: 0.12s; }
.reveal--delay-2 { animation-delay: 0.24s; }
.reveal--delay-3 { animation-delay: 0.36s; }

@keyframes rise {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes drift {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(18px, -16px, 0) scale(1.06); }
}

@keyframes pulse-mark {
  0%, 100% { transform: scale(1); box-shadow: 0 8px 18px rgba(31, 168, 122, 0.35); }
  50% { transform: scale(1.05); box-shadow: 0 10px 24px rgba(31, 168, 122, 0.48); }
}

@keyframes phone-float {
  0%, 100% { transform: translateY(0) rotate(var(--phone-rot, 4deg)); }
  50% { transform: translateY(-10px) rotate(var(--phone-rot, 4deg)); }
}

.hero-phone--back { --phone-rot: -8deg; }
.hero-phone--front { --phone-rot: 4deg; }

@keyframes bubble-in {
  from {
    opacity: 0;
    transform: translateY(8px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes typing {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.45; }
  40% { transform: translateY(-3px); opacity: 1; }
}

@keyframes chip-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

.hero-float--c {
  animation-name: chip-float-center;
}

@keyframes chip-float-center {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, -6px); }
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 48px;
  }

  .hero__visual {
    order: -1;
  }

  .hero-stage {
    width: min(100%, 360px);
    height: 380px;
  }

  .hero-phone {
    width: 200px;
  }

  .hero-phone__chat {
    min-height: 190px;
  }

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

@media (max-width: 640px) {
  .topbar__nav {
    gap: 12px;
    font-size: 0.88rem;
  }

  .brand-mark__text {
    font-size: 0.95rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal,
  .hero__orb,
  .hero-phone,
  .bubble,
  .bubble--typing i,
  .hero-float,
  .brand-mark__glyph {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }

  .hero-phone--back { transform: rotate(-8deg) !important; }
  .hero-phone--front { transform: rotate(4deg) !important; }
  .hero-float--c { transform: translateX(-50%) !important; }
}