:root {
  --teal-900: #075e59;
  --teal-700: #0b7a74;
  --teal-500: #1bb5ad;
  --teal-100: #d8f5f2;
  --ink: #14201f;
  --ink-soft: #3d4f4d;
  --muted: #6b7c7a;
  --paper: #f3faf8;
  --line: rgba(11, 122, 116, 0.16);
  --white: #ffffff;
  --shadow: 0 28px 70px rgba(7, 94, 89, 0.16);
  --radius: 18px;
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Outfit", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(27, 181, 173, 0.22), transparent 55%),
    radial-gradient(900px 500px at 90% 0%, rgba(11, 122, 116, 0.12), transparent 50%),
    linear-gradient(180deg, #f7fcfb 0%, var(--paper) 40%, #eef7f5 100%);
  min-height: 100vh;
}

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

img {
  display: block;
  max-width: 100%;
  height: auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px clamp(20px, 4vw, 48px);
  backdrop-filter: blur(12px);
  background: rgba(243, 250, 248, 0.82);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, background 0.25s ease;
}

.topbar.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(243, 250, 248, 0.94);
}

.topbar-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.topbar-brand img {
  border-radius: 7px;
}

.topbar-nav {
  display: flex;
  align-items: center;
  gap: 8px 18px;
}

.topbar-nav a {
  color: var(--ink-soft);
  font-size: 0.95rem;
  font-weight: 500;
}

.topbar-nav a:hover {
  color: var(--teal-700);
}

.topbar-cta {
  padding: 8px 14px;
  border-radius: 10px;
  background: var(--teal-700);
  color: var(--white) !important;
}

.topbar-cta:hover {
  background: var(--teal-900);
  color: var(--white) !important;
}

.hero {
  display: grid;
  grid-template-columns: minmax(280px, 0.92fr) minmax(0, 1.2fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
  min-height: calc(100vh - 64px);
  padding: clamp(28px, 5vh, 56px) 0 clamp(40px, 7vh, 72px) clamp(20px, 4vw, 48px);
  overflow: hidden;
}

.hero-brand {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 3.4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.15;
  color: var(--teal-700);
  letter-spacing: 0.02em;
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.7s ease 0.05s forwards;
}

.hero h1 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 2.6vw, 2.15rem);
  font-weight: 600;
  line-height: 1.3;
  color: var(--ink);
  max-width: 14em;
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.7s ease 0.18s forwards;
}

.hero-lead {
  margin: 0 0 28px;
  max-width: 32em;
  color: var(--ink-soft);
  font-size: 1.05rem;
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.7s ease 0.3s forwards;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.7s ease 0.42s forwards;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.98rem;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--teal-700), var(--teal-500));
  color: var(--white);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--teal-900), var(--teal-700));
}

.btn-ghost {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.55);
  color: var(--ink-soft);
}

.btn-ghost:hover {
  border-color: var(--teal-500);
  color: var(--teal-700);
}

.btn-lg {
  min-height: 52px;
  padding: 0 28px;
  font-size: 1.05rem;
}

.btn.is-disabled,
.btn[aria-disabled="true"] {
  opacity: 0.65;
  pointer-events: none;
  cursor: not-allowed;
}

.hero-visual {
  position: relative;
  min-width: 0;
  opacity: 0;
  transform: translateX(28px);
  animation: slide-in 0.9s ease 0.2s forwards;
}

.hero-shot {
  width: 100%;
  max-width: none;
  border-radius: 18px 0 0 18px;
  border: 1px solid var(--line);
  border-right: 0;
  box-shadow: var(--shadow);
  object-fit: cover;
  object-position: left top;
}

.section-head {
  max-width: 640px;
  margin-bottom: 36px;
}

.section-head h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.4vw, 2rem);
  font-weight: 700;
  line-height: 1.25;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.features,
.screens,
.workflow,
.download {
  padding: clamp(56px, 9vh, 96px) clamp(20px, 4vw, 48px);
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px 48px;
  border-top: 1px solid var(--line);
}

.feature-list li {
  padding-top: 28px;
}

.feature-list h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
  font-weight: 650;
}

.feature-list p {
  margin: 0;
  color: var(--ink-soft);
  max-width: 34em;
}

.screen-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px 24px;
}

.screen-grid figure {
  margin: 0;
  min-width: 0;
}

.screen-grid img {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--line);
  box-shadow: 0 12px 32px rgba(7, 94, 89, 0.08);
  background: var(--white);
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.screen-grid figure:hover img {
  transform: translateY(-4px);
  box-shadow: 0 18px 40px rgba(7, 94, 89, 0.14);
}

.screen-grid figcaption {
  margin-top: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-soft);
}

.workflow {
  background:
    linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.45) 20%, rgba(255, 255, 255, 0.45) 80%, transparent);
}

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

.steps li {
  padding-right: 12px;
}

.step-num {
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--teal-500);
  letter-spacing: 0.04em;
}

.steps h3 {
  margin: 0 0 8px;
  font-size: 1.12rem;
}

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

.download-panel {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  padding: clamp(36px, 6vw, 56px) clamp(20px, 4vw, 40px);
  border-radius: calc(var(--radius) + 6px);
  background:
    linear-gradient(160deg, rgba(11, 122, 116, 0.12), rgba(27, 181, 173, 0.08)),
    rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
}

.download-panel h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.3vw, 1.9rem);
}

.download-panel > p {
  margin: 0 0 24px;
  color: var(--muted);
}

.download-note {
  margin: 16px 0 0 !important;
  font-size: 0.85rem !important;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 28px clamp(20px, 4vw, 48px) 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--ink-soft);
  font-weight: 600;
}

.footer-brand img {
  border-radius: 6px;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

@keyframes rise {
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes slide-in {
  to {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: 28px clamp(20px, 4vw, 48px) 48px;
  }

  .hero-visual {
    order: -1;
  }

  .hero-shot {
    border-radius: 14px;
    border-right: 1px solid var(--line);
  }

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

  .steps li {
    padding-right: 0;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--line);
  }

  .steps li:last-child {
    border-bottom: 0;
  }
}

@media (min-width: 961px) and (max-width: 1200px) {
  .screen-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .topbar-nav a:not(.topbar-cta) {
    display: none;
  }

  .hero-brand {
    font-size: 1.7rem;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}