* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

img { max-width: 100%; }

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: #1e293b;
  line-height: 1.6;
  background: #ffffff;
  padding-top: 64px;
}

/* Colors */
:root {
  --blue: #07C160;
  --blue-dark: #06AD56;
  --blue-light: #E6F8F0;
  --yellow: #FFB400;
  --yellow-light: #FFF8E6;
  --green: #10B981;
  --green-light: #E6F9F0;
  --gray-50: #F8FAFC;
  --gray-100: #F1F5F9;
  --gray-400: #94A3B8;
  --gray-500: #64748B;
  --gray-600: #475569;
  --gray-800: #1E293B;
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  min-height: 64px;
  background: rgba(255,255,255,0.95);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--gray-100);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-inner {
  width: 100%;
  max-width: 1100px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--gray-800);
  text-decoration: none;
}

.nav-logo-icon {
  width: 32px;
  height: 32px;
  background: var(--blue);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 16px;
  font-weight: 700;
}

.nav-logo-img {
  height: 32px;
  width: auto;
  display: block;
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--gray-600);
  font-size: 15px;
  font-weight: 500;
  padding-bottom: 4px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.nav-links a:hover {
  color: var(--gray-800);
}

.nav-links a.active {
  color: var(--blue);
  border-bottom-color: var(--blue);
}

@media (max-width: 768px) {
  body {
    padding-top: 104px;
  }

  .nav {
    align-items: stretch;
  }

  .nav-inner {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    min-height: 64px;
    gap: 0;
    padding: 12px 20px;
  }

  .nav-logo {
    justify-content: flex-start;
    align-self: flex-start;
    margin-bottom: 10px;
  }

  .nav-links {
    width: 100%;
    flex-direction: row;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 24px;
    padding-top: 8px;
    border-top: 1px solid var(--gray-100);
  }

  .nav-links a {
    font-size: 15px;
    padding-bottom: 4px;
  }
}

/* Footer */
.footer {
  background: var(--gray-50);
  border-top: 1px solid var(--gray-100);
  padding: 40px 24px;
  text-align: center;
}

.footer p {
  color: var(--gray-500);
  font-size: 14px;
  line-height: 1.8;
}

.footer .footer-beian a {
  color: var(--gray-500);
  text-decoration: none;
}

.footer .footer-beian a:hover {
  text-decoration: underline;
}

/* Page Header */
.page-header {
  padding: 60px 24px;
  text-align: center;
  background: linear-gradient(180deg, var(--blue-light) 0%, #ffffff 100%);
}

.page-header .subtitle {
  display: inline-block;
  color: var(--blue);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.page-header h1 {
  font-size: 40px;
  font-weight: 800;
  color: var(--gray-800);
  max-width: 600px;
  margin: 0 auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--blue);
  color: white;
}

.btn-primary:hover {
  background: var(--blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(7,193,96,0.3);
}

.btn-download {
  background: var(--blue);
  color: white;
  padding: 16px 36px;
  font-size: 18px;
}

.btn-download:hover {
  background: var(--yellow);
  color: var(--gray-800);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255,180,0,0.4);
}

.btn-secondary {
  background: var(--gray-100);
  color: var(--gray-800);
}

.btn-secondary:hover {
  background: var(--gray-800);
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(30,41,59,0.15);
}

/* Container */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Section */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--gray-50);
}

/* Section Titles */
.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 32px;
  font-weight: 800;
  color: var(--gray-800);
  margin-bottom: 12px;
}

.section-title p {
  color: var(--gray-600);
  font-size: 16px;
  max-width: 500px;
  margin: 0 auto;
}

.feature-icon.blue { background: var(--blue-light); color: var(--blue); }
.feature-icon.green { background: var(--green-light); color: var(--green); }
.feature-icon.yellow { background: var(--yellow-light); color: var(--yellow); }

/* Feature list (features page) */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.feature-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  padding: 24px;
  border-radius: 12px;
  transition: background 0.2s;
}

.feature-item:hover {
  background: var(--gray-50);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  flex-shrink: 0;
}

.feature-content h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-content p {
  color: var(--gray-600);
  font-size: 14px;
  line-height: 1.7;
}

.feature-content ul {
  list-style: none;
  margin-top: 8px;
}

.feature-content li {
  color: var(--gray-600);
  font-size: 14px;
  padding-left: 16px;
  position: relative;
  margin-bottom: 4px;
}

.feature-content li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--blue);
  font-weight: 700;
}

/* Download page */
.download-card {
  max-width: 100%;
  background: white;
  border-radius: 16px;
  padding: 48px;
  border: 1px solid var(--gray-100);
  text-align: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.04);
}

.download-icon {
  width: 80px;
  height: 80px;
  background: var(--blue);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
  color: white;
  font-size: 36px;
  font-weight: 700;
}

.download-logo {
  height: 80px;
  width: auto;
  display: block;
  margin: 0 auto 24px;
}

.download-card h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 8px;
}

.download-card .version {
  color: var(--gray-500);
  font-size: 14px;
  margin-bottom: 24px;
}

.download-buttons {
  display: flex;
  flex-direction: row;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
}

.download-buttons .btn {
  justify-content: center;
  width: auto;
  min-width: 240px;
}

.download-card .meta {
  color: var(--gray-500);
  font-size: 14px;
  line-height: 1.8;
}

.sys-req {
  max-width: 100%;
  margin: 40px 0 0;
}

.sys-req h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
  text-align: center;
}

.sys-req ul {
  list-style: none;
  background: white;
  border-radius: 12px;
  border: 1px solid var(--gray-100);
  overflow: hidden;
}

.sys-req li {
  padding: 14px 24px;
  border-bottom: 1px solid var(--gray-100);
  font-size: 14px;
  color: var(--gray-600);
  display: flex;
  justify-content: space-between;
}

.sys-req li:last-child { border-bottom: none; }

.sys-req li span { color: var(--gray-800); font-weight: 500; }

/* Hero */
.hero {
  padding: 100px 24px 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  max-width: 1100px;
  margin: 0 auto;
  align-items: center;
}

.hero-text h1 {
  font-size: 44px;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--gray-800);
}

.hero-text h1 span {
  color: var(--blue);
}

.hero-text p {
  font-size: 18px;
  color: var(--gray-600);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
}

.hero-mockup {
  display: flex;
  justify-content: center;
  align-items: center;
}

.mockup-box {
  width: 320px;
  height: 420px;
  background: linear-gradient(135deg, var(--blue-light), #D3F5E3);
  border-radius: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 16px;
  border: 1px solid rgba(7,193,96,0.1);
  box-shadow: 0 20px 40px rgba(7,193,96,0.1);
}

.mockup-box .kb-icon {
  font-size: 64px;
  opacity: 0.3;
  color: var(--blue);
}

.mockup-box .kb-text {
  font-size: 20px;
  color: var(--blue);
  font-weight: 600;
}

/* Responsive */
/* ============================================
   Responsive
   ============================================ */

/* Large desktop */
@media (min-width: 1200px) {
  .hero {
    padding: 160px 24px 100px;
  }
  .hero-text h1 { font-size: 52px; }
  .mockup-box { width: 360px; height: 460px; }
}

/* Tablet / small desktop */
@media (max-width: 1024px) {
  .hero-inner { gap: 40px; }
  .hero-text h1 { font-size: 40px; }
}

/* Mobile & tablet portrait */
@media (max-width: 768px) {
  .container { padding: 0 20px; }

  .section { padding: 56px 0; }

  .page-header { padding: 110px 20px 44px; }
  .page-header h1 { font-size: 30px; }

  .section-title { margin-bottom: 36px; }
  .section-title h2 { font-size: 26px; }

  /* Hero */
  .hero {
    min-height: auto;
    padding: 40px 20px 56px;
  }
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .hero-text {
    text-align: center;
  }
  .hero-text h1 { font-size: 34px; margin-bottom: 14px; }
  .hero-text p { font-size: 16px; margin-bottom: 24px; }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    width: 100%;
  }
  .hero-actions .btn {
    justify-content: center;
    width: 100%;
    padding: 14px 24px;
  }
  .mockup-box { width: 100%; height: 300px; gap: 12px; }
  .mockup-box .kb-icon { font-size: 48px; }
  .mockup-box .kb-text { font-size: 17px; }

  /* Features */
  .feature-grid { grid-template-columns: 1fr; gap: 16px; }
  .feature-item { padding: 20px; }

  /* Download */
  .download-card { padding: 32px 20px; }
  .download-buttons {
    flex-direction: column;
    align-items: stretch;
  }
  .download-buttons .btn {
    width: 100%;
    min-width: 0;
  }
}

/* Small phones */
@media (max-width: 480px) {
  .hero-text h1 { font-size: 28px; }
  .download-card .btn {
    justify-content: center;
    width: 100%;
  }
  .sys-req li { flex-direction: column; gap: 4px; }
}