:root {
  --tg-blue: #2aabee;
  --tg-blue-deep: #1b8fd0;
  --blue-ink: #1593d8;
  --violet: #6e8cff;
  --bg: #f6fafd;
  --bg-soft: #edf4fa;
  --card: #ffffff;
  --line: #dbe8f3;
  --ink: #0f2740;
  --ink-soft: #51677e;
  --radius: 16px;
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: rgba(42, 171, 238, 0.28); }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

a { color: var(--blue-ink); text-decoration: none; }

h1, h2, h3 { line-height: 1.3; margin: 0 0 0.5em; }

section[id] { scroll-margin-top: 80px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(246, 250, 253, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ink);
}

.brand img {
  display: block;
  filter: drop-shadow(0 2px 10px rgba(42, 171, 238, 0.4));
}

.nav-links {
  display: flex;
  gap: 26px;
  list-style: none;
  margin: 0 auto 0 0;
  padding: 0;
}

.nav-links a {
  color: var(--ink-soft);
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

.nav-links a:hover { color: var(--blue-ink); }

.btn {
  display: inline-block;
  padding: 11px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease, color 0.18s ease, background 0.18s ease;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: linear-gradient(135deg, var(--tg-blue), var(--tg-blue-deep));
  color: #fff;
  box-shadow: 0 8px 24px rgba(42, 171, 238, 0.4);
}

.btn-primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(110deg, transparent 30%, rgba(255, 255, 255, 0.4) 50%, transparent 70%);
  transform: translateX(-130%);
  transition: transform 0.6s ease;
}

.btn-primary:hover::after { transform: translateX(130%); }

.btn-primary:hover { box-shadow: 0 12px 32px rgba(42, 171, 238, 0.55); }

.btn-outline {
  border-color: #b9d4ea;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.7);
}

.btn-outline:hover { border-color: var(--tg-blue); color: var(--blue-ink); }

.btn-ghost {
  color: var(--ink);
  border-color: #c3d9ec;
}

.btn-ghost:hover { border-color: var(--tg-blue); color: var(--blue-ink); }

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

.orb-a {
  width: 480px;
  height: 480px;
  top: -160px;
  right: -80px;
  background: radial-gradient(circle, rgba(42, 171, 238, 0.28), transparent 65%);
  animation: drift 16s ease-in-out infinite alternate;
}

.orb-b {
  width: 400px;
  height: 400px;
  bottom: -200px;
  left: -120px;
  background: radial-gradient(circle, rgba(110, 140, 255, 0.22), transparent 65%);
  animation: drift 20s ease-in-out infinite alternate-reverse;
}

.orb-c {
  width: 420px;
  height: 420px;
  top: -200px;
  left: 50%;
  margin-left: -210px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.45), transparent 65%);
}

@keyframes drift {
  from { transform: translate(0, 0) scale(1); }
  to { transform: translate(40px, 30px) scale(1.12); }
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 96px 0 104px;
  background: linear-gradient(180deg, #eef6fc, var(--bg));
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(42, 130, 200, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 130, 200, 0.1) 1px, transparent 1px);
  background-size: 44px 44px;
  -webkit-mask-image: radial-gradient(900px 520px at 60% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(900px 520px at 60% 0%, #000 30%, transparent 75%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 18px;
  padding: 6px 16px;
  border-radius: 999px;
  border: 1px solid rgba(42, 171, 238, 0.45);
  background: rgba(42, 171, 238, 0.08);
  color: var(--blue-ink);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
}

.pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--tg-blue);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(42, 171, 238, 0.5); }
  50% { box-shadow: 0 0 0 7px rgba(42, 171, 238, 0); }
}

.hero h1 {
  font-size: clamp(2rem, 4.4vw, 3.1rem);
  letter-spacing: -0.01em;
  text-wrap: balance;
}

.grad {
  background: linear-gradient(92deg, #0ea2e8, var(--tg-blue) 55%, var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lead {
  color: var(--ink-soft);
  font-size: 1.08rem;
  max-width: 34em;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 30px 0 8px;
}

.hero-points {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.hero-points li {
  padding-left: 26px;
  position: relative;
  margin-bottom: 8px;
}

.hero-points li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--blue-ink);
  font-weight: 700;
}

.hero-visual { position: relative; }

.chat-mock {
  position: relative;
  background: #ffffff;
  border: 1px solid #cfe6f7;
  border-radius: 22px;
  padding: 18px;
  box-shadow: 0 30px 60px rgba(23, 93, 153, 0.16), 0 6px 18px rgba(23, 93, 153, 0.08);
  font-size: 0.9rem;
  transform: perspective(1400px) rotateY(-7deg) rotateX(2deg);
  transition: transform 0.5s ease;
}

.chat-mock:hover { transform: perspective(1400px) rotateY(0deg) rotateX(0deg); }

.chat-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--ink);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.chat-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--tg-blue), var(--tg-blue-deep));
  box-shadow: 0 0 8px rgba(42, 171, 238, 0.7);
}

.msg {
  border-radius: 12px;
  padding: 10px 14px;
  margin-bottom: 10px;
  max-width: 92%;
}

.msg-name {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  margin-bottom: 2px;
  color: var(--blue-ink);
}

.msg-normal {
  background: #f1f6fb;
  color: #2c4258;
}

.msg-spam {
  background: #fdecec;
  border: 1px dashed rgba(224, 86, 86, 0.5);
  color: #c24343;
}

.msg-spam .msg-name { color: #e05656; }

.msg-spam s {
  text-decoration: none;
  position: relative;
}

.msg-spam s::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 55%;
  height: 2px;
  border-radius: 2px;
  background: #e05656;
  transform-origin: left center;
  animation: strike 11s ease infinite;
}

.msg-bot {
  background: #e9f5fe;
  border: 1px solid rgba(42, 171, 238, 0.45);
  color: var(--ink);
  box-shadow: 0 4px 16px rgba(42, 171, 238, 0.15);
}

.msg-actions {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}

.chip {
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid rgba(27, 143, 208, 0.45);
  color: var(--blue-ink);
  background: #ffffff;
}

.m1 { animation: m1 11s ease infinite; }
.m2 { animation: m2 11s ease infinite; }
.m3 { animation: m3 11s ease infinite; }
.m4 { animation: m4 11s ease infinite; }

@keyframes m1 {
  0% { opacity: 0; transform: translateY(10px); }
  4%, 93% { opacity: 1; transform: none; }
  98%, 100% { opacity: 0; transform: none; }
}

@keyframes m2 {
  0%, 14% { opacity: 0; transform: translateY(10px); background: #f1f6fb; border-color: transparent; color: #2c4258; }
  19%, 32% { opacity: 1; transform: none; background: #f1f6fb; border-color: transparent; color: #2c4258; }
  37%, 93% { opacity: 1; transform: none; background: #fdecec; border-color: rgba(224, 86, 86, 0.5); color: #c24343; }
  98%, 100% { opacity: 0; transform: none; }
}

@keyframes strike {
  0%, 33% { transform: scaleX(0); }
  39%, 100% { transform: scaleX(1); }
}

@keyframes m3 {
  0%, 42% { opacity: 0; transform: translateY(12px) scale(0.96); }
  48%, 93% { opacity: 1; transform: none; }
  98%, 100% { opacity: 0; transform: none; }
}

@keyframes m4 {
  0%, 66% { opacity: 0; transform: translateY(10px); }
  72%, 93% { opacity: 1; transform: none; }
  98%, 100% { opacity: 0; transform: none; }
}

.float-chip {
  position: absolute;
  top: -16px;
  right: -8px;
  padding: 8px 16px;
  border-radius: 999px;
  background: #ffffff;
  border: 1px solid rgba(42, 171, 238, 0.5);
  color: var(--blue-ink);
  font-size: 0.82rem;
  font-weight: 600;
  box-shadow: 0 10px 26px rgba(23, 93, 153, 0.18);
  animation: floaty 5s ease-in-out infinite alternate;
}

@keyframes floaty {
  from { transform: translateY(0); }
  to { transform: translateY(-10px); }
}

.stats {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(42, 171, 238, 0.06), rgba(255, 255, 255, 0.4));
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding-top: 34px;
  padding-bottom: 34px;
}

.stat { text-align: center; }

.stat strong {
  display: block;
  font-size: 1.7rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  background: linear-gradient(92deg, #0ea2e8, var(--tg-blue) 60%, var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stat span {
  color: var(--ink-soft);
  font-size: 0.88rem;
}

.section { position: relative; padding: 92px 0; }

.section-alt { background: var(--bg-soft); }

.section-tag {
  width: fit-content;
  margin: 0 auto 14px;
  padding: 5px 14px;
  border-radius: 999px;
  border: 1px solid rgba(42, 171, 238, 0.4);
  background: rgba(42, 171, 238, 0.07);
  color: var(--blue-ink);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
}

.section h2 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  text-align: center;
}

.section-lead {
  text-align: center;
  color: var(--ink-soft);
  max-width: 38em;
  margin: 0 auto 50px;
}

.feature-grid, .stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

.stack-grid { margin-top: 44px; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.card:hover {
  transform: translateY(-5px);
  border-color: #8ecdf2;
  box-shadow: 0 18px 40px rgba(23, 93, 153, 0.13), 0 4px 12px rgba(23, 93, 153, 0.06);
}

.icon {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  margin-bottom: 16px;
  border-radius: 13px;
  border: 1px solid rgba(42, 171, 238, 0.35);
  background: linear-gradient(135deg, rgba(42, 171, 238, 0.14), rgba(110, 140, 255, 0.08));
  color: var(--blue-ink);
  box-shadow: 0 4px 14px rgba(42, 171, 238, 0.16);
}

.icon svg { width: 22px; height: 22px; }

.card h3 { font-size: 1.05rem; }

.card p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.pipeline {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 18px;
}

.pipeline::before {
  content: "";
  position: absolute;
  left: 41px;
  top: 28px;
  bottom: 28px;
  width: 2px;
  background: linear-gradient(180deg, rgba(42, 171, 238, 0.65), rgba(42, 171, 238, 0.3), rgba(110, 140, 255, 0.15));
}

.pipeline li {
  counter-increment: step;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px 22px 78px;
  position: relative;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.pipeline li:hover {
  border-color: #8ecdf2;
  box-shadow: 0 14px 34px rgba(23, 93, 153, 0.12);
}

.pipeline li::before {
  content: counter(step);
  position: absolute;
  left: 24px;
  top: 22px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--tg-blue), var(--tg-blue-deep));
  color: #fff;
  font-weight: 800;
  display: grid;
  place-items: center;
  box-shadow: 0 6px 16px rgba(42, 171, 238, 0.45);
}

.pipeline h3 { font-size: 1.02rem; margin-bottom: 4px; }

.pipeline p { margin: 0; color: var(--ink-soft); font-size: 0.92rem; }

.faq-list {
  max-width: 760px;
  margin: 40px auto 0;
  display: grid;
  gap: 12px;
}

.faq-list details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 22px;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.faq-list details:hover, .faq-list details[open] {
  border-color: #8ecdf2;
  box-shadow: 0 12px 30px rgba(23, 93, 153, 0.1);
}

.faq-list summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  position: relative;
  padding-right: 28px;
}

.faq-list summary::-webkit-details-marker { display: none; }

.faq-list summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  color: var(--blue-ink);
  font-size: 1.3rem;
  font-weight: 400;
  transition: transform 0.2s ease;
}

.faq-list details[open] summary::after {
  content: "−";
  transform: translateY(-50%) rotate(180deg);
}

.faq-list p {
  margin: 12px 0 0;
  color: var(--ink-soft);
  font-size: 0.94rem;
}

.cta-final { padding-top: 24px; }

.cta-box {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--tg-blue), #1b7fc4);
  border-radius: 26px;
  text-align: center;
  padding: 66px 32px;
  color: #fff;
  box-shadow: 0 30px 60px rgba(23, 93, 153, 0.3);
}

.cta-box h2, .cta-box p, .cta-box .cta-row { position: relative; }

.cta-box p { color: rgba(255, 255, 255, 0.85); margin-top: 0; }

.cta-box .cta-row { justify-content: center; }

.cta-box .btn-primary {
  background: #ffffff;
  color: #1b7fc4;
  box-shadow: 0 10px 26px rgba(8, 50, 84, 0.3);
}

.cta-box .btn-primary:hover { box-shadow: 0 14px 34px rgba(8, 50, 84, 0.4); }

.cta-box .btn-outline {
  border-color: rgba(255, 255, 255, 0.65);
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.cta-box .btn-outline:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 36px 0;
  font-size: 0.9rem;
  background: #fbfdff;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
}

.site-footer .brand { font-size: 1rem; }

.site-footer nav {
  display: flex;
  gap: 20px;
  margin: 0 auto;
}

.site-footer nav a { color: var(--ink-soft); transition: color 0.2s ease; }

.site-footer nav a:hover { color: var(--blue-ink); }

.copyright { margin: 0; color: var(--ink-soft); }

.js .reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.js .reveal.in {
  opacity: 1;
  transform: none;
}

.feature-grid .reveal:nth-child(2), .stack-grid .reveal:nth-child(2), .stats-grid .reveal:nth-child(2) { transition-delay: 0.07s; }
.feature-grid .reveal:nth-child(3), .stack-grid .reveal:nth-child(3), .stats-grid .reveal:nth-child(3) { transition-delay: 0.14s; }
.feature-grid .reveal:nth-child(4), .stack-grid .reveal:nth-child(4), .stats-grid .reveal:nth-child(4) { transition-delay: 0.21s; }
.faq-list .reveal:nth-child(2), .pipeline .reveal:nth-child(2) { transition-delay: 0.07s; }
.faq-list .reveal:nth-child(3), .pipeline .reveal:nth-child(3) { transition-delay: 0.14s; }
.faq-list .reveal:nth-child(4), .pipeline .reveal:nth-child(4) { transition-delay: 0.21s; }
.faq-list .reveal:nth-child(5), .pipeline .reveal:nth-child(5) { transition-delay: 0.28s; }

@media (max-width: 860px) {
  .hero { padding: 56px 0 64px; }
  .hero-grid { grid-template-columns: 1fr; gap: 44px; }
  .nav-links { display: none; }
  .section { padding: 64px 0; }
  .pipeline::before { left: 39px; }
  .pipeline li { padding-left: 72px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .chat-mock { transform: none; }
  .float-chip { right: 6px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; }
  .chat-mock { transform: none; }
}