/* ===== VARIABLES ===== */
:root {
  --blue-primary: #1a73e8;
  --blue-dark: #1557b0;
  --blue-light: #e8f0fe;
  --green: #34a853;
  --red: #ea4335;
  --yellow: #fbbc04;
  --text-dark: #202124;
  --text-mid: #3c4043;
  --text-soft: #5f6368;
  --text-light: #80868b;
  --border: #dadce0;
  --bg-white: #fff;
  --bg-gray: #f8f9fa;
  --bg-dark: #202124;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.12), 0 1px 2px rgba(0,0,0,.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,.1);
  --shadow-lg: 0 8px 30px rgba(0,0,0,.14);
  --radius: 8px;
  --radius-lg: 16px;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-display: 'Google Sans', 'Noto Sans SC', sans-serif;
  --transition: .2s cubic-bezier(.4,0,.2,1);
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  color: var(--text-dark);
  background: var(--bg-white);
  line-height: 1.6;
  font-size: 16px;
}
a { color: var(--blue-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--blue-dark); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

/* ===== HEADER ===== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-white);
  border-bottom: 1px solid var(--border);
  height: 64px;
  display: flex; align-items: center;
  box-shadow: var(--shadow-sm);
}
.header-inner {
  max-width: 1200px; margin: 0 auto; width: 100%;
  padding: 0 24px;
  display: flex; align-items: center; gap: 32px;
}
.site-logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.site-logo img { width: 150px; height:42px; }
.logo-text { font-size: 18px; font-weight: 600; color: var(--text-dark); font-family: var(--font-display); }
.logo-text span { color: var(--blue-primary); }

.main-nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav-link {
  padding: 8px 14px;
  border-radius: 24px;
  font-size: 14px;
  color: var(--text-mid);
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
}
.nav-link:hover { background: var(--bg-gray); color: var(--blue-primary); }
.nav-link.active { color: var(--blue-primary); background: var(--blue-light); }
.nav-link.btn-dl {
  background: var(--blue-primary); color: #fff; padding: 8px 20px;
}
.nav-link.btn-dl:hover { background: var(--blue-dark); color: #fff; }

.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.hamburger span {
  display: block; width: 22px; height: 2px;
  background: var(--text-mid); border-radius: 2px;
  margin: 5px 0; transition: var(--transition);
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--bg-dark); color: #bdc1c6;
  padding: 56px 24px 32px;
  margin-top: 80px;
}
.footer-inner {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
}
.footer-brand .logo-text { color: #fff; }
.footer-brand p { margin-top: 12px; font-size: 14px; color: #9aa0a6; line-height: 1.7; max-width: 280px; }
.footer-col h4 { color: #e8eaed; font-size: 13px; font-weight: 600; letter-spacing: .6px; text-transform: uppercase; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; color: #9aa0a6; padding: 4px 0; transition: color var(--transition); }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  max-width: 1200px; margin: 40px auto 0;
  padding-top: 24px; border-top: 1px solid #3c4043;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; color: #9aa0a6; flex-wrap: wrap; gap: 12px;
}
.footer-links { display: flex; gap: 20px; }
.footer-links a { color: #9aa0a6; font-size: 13px; }
.footer-links a:hover { color: #fff; }

/* ===== HERO ===== */
.hero {
  background: linear-gradient(135deg, #e8f0fe 0%, #f0f7ff 50%, #e6f4ea 100%);
  padding: 80px 24px 100px;
  text-align: center;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(26,115,232,.08) 0%, transparent 70%);
}
.hero-inner { max-width: 800px; margin: 0 auto; position: relative; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; border: 1px solid var(--border);
  border-radius: 24px; padding: 6px 16px;
  font-size: 13px; color: var(--text-mid);
  margin-bottom: 28px; box-shadow: var(--shadow-sm);
}
.hero-badge i { color: var(--blue-primary); }
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700; color: var(--text-dark);
  font-family: var(--font-display);
  line-height: 1.2; margin-bottom: 20px;
}
.hero h1 em { font-style: normal; color: var(--blue-primary); }
.hero-sub {
  font-size: 18px; color: var(--text-soft);
  max-width: 600px; margin: 0 auto 40px;
  line-height: 1.7;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary {
  background: var(--blue-primary); color: #fff;
  padding: 14px 32px; border-radius: 24px;
  font-size: 16px; font-weight: 600;
  display: inline-flex; align-items: center; gap: 8px;
  transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
  box-shadow: 0 2px 8px rgba(26,115,232,.3);
}
.btn-primary:hover { background: var(--blue-dark); color: #fff; transform: translateY(-1px); box-shadow: 0 4px 16px rgba(26,115,232,.4); }
.btn-secondary {
  background: #fff; color: var(--blue-primary);
  padding: 14px 28px; border-radius: 24px;
  font-size: 16px; font-weight: 500;
  border: 1px solid var(--border);
  display: inline-flex; align-items: center; gap: 8px;
  transition: var(--transition);
}
.btn-secondary:hover { border-color: var(--blue-primary); background: var(--blue-light); }
.hero-note { margin-top: 20px; font-size: 13px; color: var(--text-light); }
.hero-img {
  margin-top: 60px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  max-width: 900px; margin-left: auto; margin-right: auto;
}
.hero-img img { width: 100%; }

/* ===== SECTION COMMON ===== */
section { padding: 72px 24px; }
.section-inner { max-width: 1200px; margin: 0 auto; }
.section-label {
  font-size: 12px; font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; color: var(--blue-primary);
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(26px, 3.5vw, 40px);
  font-weight: 700; color: var(--text-dark);
  font-family: var(--font-display);
  line-height: 1.25; margin-bottom: 16px;
}
.section-sub {
  font-size: 17px; color: var(--text-soft); max-width: 580px; line-height: 1.7;
}
.text-center { text-align: center; }
.text-center .section-sub { margin-left: auto; margin-right: auto; }

/* ===== FEATURE GRID ===== */
.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px;
  margin-top: 48px;
}
.feature-card {
  background: var(--bg-white); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 32px;
  transition: box-shadow var(--transition), transform var(--transition);
}
.feature-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.card-icon {
  width: 52px; height: 52px; border-radius: 14px;
  background: var(--blue-light); color: var(--blue-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; margin-bottom: 20px;
}
.card-icon.green { background: #e6f4ea; color: var(--green); }
.card-icon.red { background: #fce8e6; color: var(--red); }
.card-icon.yellow { background: #fef7e0; color: #f9a825; }
.feature-card h3 { font-size: 17px; font-weight: 600; margin-bottom: 10px; color: var(--text-dark); }
.feature-card p { font-size: 14px; color: var(--text-soft); line-height: 1.7; }

/* ===== SPLIT SECTION ===== */
.split-section { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.split-section.reverse { direction: rtl; }
.split-section.reverse > * { direction: ltr; }
.split-text .section-sub { max-width: 100%; }
.split-text .btn-primary, .split-text .btn-secondary { margin-top: 28px; }
.split-img { border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-md); }
.split-img img { width: 100%; }

/* ===== STEPS ===== */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 32px; margin-top: 48px; }
.step { text-align: center; }
.step-num {
  width: 52px; height: 52px; border-radius: 50%;
  background: var(--blue-primary); color: #fff;
  font-size: 22px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 20px;
}
.step h3 { font-size: 17px; font-weight: 600; margin-bottom: 10px; }
.step p { font-size: 14px; color: var(--text-soft); line-height: 1.7; }

/* ===== CTA BAND ===== */
.cta-band {
  background: linear-gradient(135deg, #1a73e8, #0d47a1);
  color: #fff; text-align: center; padding: 72px 24px;
}
.cta-band h2 { font-size: clamp(26px, 3vw, 36px); font-weight: 700; margin-bottom: 14px; }
.cta-band p { font-size: 17px; opacity: .85; margin-bottom: 36px; max-width: 520px; margin-left: auto; margin-right: auto; }
.btn-white {
  background: #fff; color: var(--blue-primary);
  padding: 14px 32px; border-radius: 24px;
  font-size: 16px; font-weight: 600;
  display: inline-flex; align-items: center; gap: 8px;
  transition: var(--transition);
}
.btn-white:hover { background: #e8f0fe; color: var(--blue-dark); }

/* ===== STATS ===== */
.stats-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 24px; }
.stat-item { text-align: center; padding: 32px 16px; }
.stat-num { font-size: 42px; font-weight: 800; color: var(--blue-primary); font-family: var(--font-display); line-height: 1; }
.stat-unit { font-size: 22px; font-weight: 700; color: var(--blue-primary); }
.stat-desc { font-size: 15px; color: var(--text-soft); margin-top: 8px; }

/* ===== TABLE ===== */
.compare-table { width: 100%; border-collapse: collapse; margin-top: 40px; }
.compare-table th { background: var(--bg-gray); padding: 16px; font-size: 14px; font-weight: 600; color: var(--text-dark); border-bottom: 2px solid var(--border); text-align: left; }
.compare-table td { padding: 14px 16px; border-bottom: 1px solid var(--border); font-size: 14px; color: var(--text-mid); }
.compare-table tr:hover td { background: var(--bg-gray); }
.check-yes { color: var(--green); font-size: 18px; }
.check-no { color: var(--text-light); font-size: 18px; }

/* ===== FAQ ===== */
.faq-list { margin-top: 40px; max-width: 800px; margin-left: auto; margin-right: auto; }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  width: 100%; background: none; border: none; cursor: pointer;
  padding: 20px 0; display: flex; justify-content: space-between; align-items: center;
  font-size: 16px; font-weight: 600; color: var(--text-dark);
  text-align: left; transition: color var(--transition);
}
.faq-q:hover { color: var(--blue-primary); }
.faq-q i { transition: transform .25s; flex-shrink: 0; margin-left: 16px; color: var(--blue-primary); }
.faq-item.open .faq-q i { transform: rotate(180deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease, padding .3s; }
.faq-item.open .faq-a { max-height: 400px; padding-bottom: 20px; }
.faq-a p { color: var(--text-soft); line-height: 1.75; font-size: 15px; }

/* ===== PAGE BANNER ===== */
.page-banner {
  background: linear-gradient(135deg, #e8f0fe 0%, #f0f7ff 100%);
  padding: 64px 24px;
  text-align: center;
}
.page-banner h1 { font-size: clamp(28px, 4vw, 44px); font-weight: 700; color: var(--text-dark); font-family: var(--font-display); margin-bottom: 16px; }
.page-banner p { font-size: 17px; color: var(--text-soft); max-width: 600px; margin: 0 auto; }

/* ===== DOWNLOAD PAGE ===== */
.dl-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; margin-top: 48px; }
.dl-card {
  border: 2px solid var(--border); border-radius: var(--radius-lg);
  padding: 36px 28px; text-align: center;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.dl-card:hover { border-color: var(--blue-primary); box-shadow: var(--shadow-md); }
.dl-card.featured { border-color: var(--blue-primary); background: var(--blue-light); }
.dl-icon { font-size: 48px; margin-bottom: 20px; }
.dl-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.dl-card .version { font-size: 13px; color: var(--text-light); margin-bottom: 16px; }
.dl-card ul { text-align: left; margin: 20px 0; }
.dl-card ul li { font-size: 14px; color: var(--text-soft); padding: 5px 0; display: flex; align-items: flex-start; gap: 8px; }
.dl-card ul li i { color: var(--green); margin-top: 2px; flex-shrink: 0; }
.dl-card .btn-primary, .dl-card .btn-secondary { width: 100%; justify-content: center; margin-top: 8px; }
.dl-note { font-size: 12px; color: var(--text-light); margin-top: 12px; }

/* ===== SECURITY PAGE ===== */
.security-points { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; margin-top: 40px; }
.sec-point { background: var(--bg-gray); border-radius: var(--radius-lg); padding: 28px; }
.sec-point i { font-size: 28px; color: var(--blue-primary); margin-bottom: 14px; }
.sec-point h3 { font-size: 17px; font-weight: 600; margin-bottom: 10px; }
.sec-point p { font-size: 14px; color: var(--text-soft); line-height: 1.7; }

/* ===== EXTENSIONS PAGE ===== */
.ext-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 20px; margin-top: 40px; }
.ext-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; transition: box-shadow var(--transition);
  display: flex; flex-direction: column; gap: 12px;
}
.ext-card:hover { box-shadow: var(--shadow-md); }
.ext-card-head { display: flex; align-items: center; gap: 12px; }
.ext-icon { width: 44px; height: 44px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 22px; flex-shrink: 0; }
.ext-card h3 { font-size: 15px; font-weight: 600; }
.ext-card p { font-size: 13px; color: var(--text-soft); line-height: 1.6; }
.ext-meta { display: flex; align-items: center; justify-content: space-between; margin-top: auto; }
.ext-rating { font-size: 13px; color: var(--text-soft); display: flex; align-items: center; gap: 4px; }
.ext-rating i { color: var(--yellow); }
.btn-ext { font-size: 13px; color: var(--blue-primary); font-weight: 600; padding: 6px 14px; border: 1px solid var(--blue-primary); border-radius: 16px; transition: var(--transition); }
.btn-ext:hover { background: var(--blue-primary); color: #fff; }

/* ===== ENTERPRISE PAGE ===== */
.plan-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; margin-top: 40px; }
.plan-card { border: 2px solid var(--border); border-radius: var(--radius-lg); padding: 36px 28px; }
.plan-card.featured { border-color: var(--blue-primary); position: relative; overflow: hidden; }
.plan-badge { position: absolute; top: 16px; right: -30px; background: var(--blue-primary); color: #fff; font-size: 12px; font-weight: 700; padding: 4px 40px; transform: rotate(35deg); }
.plan-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.plan-card .plan-price { font-size: 36px; font-weight: 800; color: var(--text-dark); margin: 16px 0 4px; }
.plan-card .plan-price span { font-size: 16px; font-weight: 400; color: var(--text-soft); }
.plan-card .plan-desc { font-size: 14px; color: var(--text-soft); margin-bottom: 28px; }
.plan-card ul { display: flex; flex-direction: column; gap: 12px; margin-bottom: 32px; }
.plan-card ul li { font-size: 14px; color: var(--text-mid); display: flex; align-items: flex-start; gap: 10px; }
.plan-card ul li i { color: var(--green); flex-shrink: 0; margin-top: 1px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 960px) {
  .split-section { grid-template-columns: 1fr; gap: 40px; }
  .split-section.reverse { direction: ltr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .main-nav { display: none; position: fixed; top: 64px; left: 0; right: 0; bottom: 0; background: #fff; flex-direction: column; align-items: flex-start; gap: 4px; padding: 16px; overflow-y: auto; z-index: 99; box-shadow: var(--shadow-lg); }
  .main-nav.open { display: flex; }
  .nav-link { width: 100%; padding: 12px 16px; border-radius: var(--radius); }
  .hamburger { display: block; margin-left: auto; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 12px; }
  section { padding: 48px 20px; }
  .hero { padding: 56px 20px 72px; }
}
@media (max-width: 480px) {
  .hero-actions { flex-direction: column; align-items: center; }
  .btn-primary, .btn-secondary { width: 100%; max-width: 320px; justify-content: center; }
  .stats-row { grid-template-columns: 1fr 1fr; }
}