/* ========================================
   Spectrum Flow / Color Ribbon Theme
   Bright white base + Google brand colors
   ======================================== */

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #202124;
  background: #fff;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: #1a73e8; text-decoration: none; transition: color .2s; }
a:hover { color: #1557b0; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

/* --- Keyframes --- */
@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
@keyframes fadeUp { from { opacity: 0; transform: translateY(24px); } to { opacity: 1; transform: translateY(0); } }
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes ribbon { from { background-position: 0 0; } to { background-position: 200% 0; } }

/* --- Utility --- */
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.wrap-narrow { max-width: 960px; margin: 0 auto; padding: 0 24px; }
.sec { padding: 80px 0; }
.sec-alt { background: #f8f9fa; }
.sec-blue { background: linear-gradient(135deg, #e8f0fe 0%, #f8f9fa 100%); }
.sec-dark { background: #202124; color: #e8eaed; }
.sec-dark a { color: #8ab4f8; }

/* --- Color Ribbon Divider --- */
.ribbon-bar {
  height: 4px;
  background: linear-gradient(90deg, #4285f4 0%, #4285f4 25%, #ea4335 25%, #ea4335 50%, #fbbc05 50%, #fbbc05 75%, #34a853 75%, #34a853 100%);
  background-size: 200% 100%;
  animation: ribbon 8s linear infinite;
}

/* --- Top Navigation --- */
.topnav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid #e8eaed;
}
.topnav-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  height: 64px;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-size: 20px; font-weight: 700; color: #202124;
}
.nav-brand svg { width: 32px; height: 32px; flex-shrink: 0; }
.nav-brand span { color: #4285f4; }
.nav-list { display: flex; align-items: center; gap: 8px; }
.nav-item {
  padding: 8px 18px; border-radius: 24px;
  font-size: 14px; font-weight: 500; color: #5f6368;
  transition: background .2s, color .2s;
}
.nav-item:hover { background: #e8f0fe; color: #1a73e8; }
.nav-item.on {
  background: #1a73e8; color: #fff;
}
.nav-dl { margin-left: 12px; }

/* --- Buttons --- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 28px; border-radius: 8px; border: none;
  font-size: 15px; font-weight: 600; cursor: pointer;
  transition: background .2s, box-shadow .2s, transform .1s;
  text-decoration: none; line-height: 1.4;
}
.btn:active { transform: scale(.97); }
.btn-blue { background: #1a73e8; color: #fff; }
.btn-blue:hover { background: #1557b0; box-shadow: 0 4px 12px rgba(26,115,232,.35); color: #fff; }
.btn-red { background: #ea4335; color: #fff; }
.btn-red:hover { background: #d9304e; box-shadow: 0 4px 12px rgba(234,67,53,.35); color: #fff; }
.btn-green { background: #34a853; color: #fff; }
.btn-green:hover { background: #2d9249; box-shadow: 0 4px 12px rgba(52,168,83,.35); color: #fff; }
.btn-outline {
  background: transparent; color: #1a73e8;
  border: 2px solid #1a73e8;
}
.btn-outline:hover { background: #e8f0fe; color: #1557b0; }
.btn-outline-w {
  background: transparent; color: #fff;
  border: 2px solid rgba(255,255,255,.6);
}
.btn-outline-w:hover { background: rgba(255,255,255,.12); border-color: #fff; color: #fff; }
.btn-white { background: #fff; color: #1a73e8; }
.btn-white:hover { background: #f8f9fa; box-shadow: 0 4px 12px rgba(0,0,0,.12); }
.btn-lg { padding: 16px 36px; font-size: 17px; border-radius: 12px; }
.btn-sm { padding: 8px 18px; font-size: 13px; border-radius: 6px; }
.btn:disabled { opacity: .6; cursor: not-allowed; }

/* --- Section Header --- */
.sec-head { text-align: center; margin-bottom: 56px; }
.sec-tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 16px; border-radius: 20px;
  font-size: 13px; font-weight: 600; letter-spacing: .5px;
  margin-bottom: 16px;
}
.sec-tag-blue { background: #e8f0fe; color: #1a73e8; }
.sec-tag-red { background: #fce8e6; color: #ea4335; }
.sec-tag-green { background: #e6f4ea; color: #34a853; }
.sec-tag-yellow { background: #fef7e0; color: #f9ab00; }
.sec-tag-dot {
  width: 8px; height: 8px; border-radius: 50%;
}
.sec-title {
  font-size: 36px; font-weight: 700; color: #202124;
  line-height: 1.3; margin-bottom: 16px;
}
.sec-title-light { color: #e8eaed; }
.sec-sub {
  font-size: 17px; color: #5f6368; max-width: 640px;
  margin: 0 auto; line-height: 1.7;
}
.sec-sub-light { color: #9aa0a6; }

/* --- Hero --- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(160deg, #4285f4 0%, #5e97f6 30%, #7b9ff7 60%, #a8c7fa 100%);
  padding: 100px 0 80px;
}
.hero::before {
  content: ''; position: absolute; top: -200px; right: -200px;
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(251,188,5,.25) 0%, transparent 70%);
}
.hero::after {
  content: ''; position: absolute; bottom: -150px; left: -150px;
  width: 400px; height: 400px; border-radius: 50%;
  background: radial-gradient(circle, rgba(234,67,53,.2) 0%, transparent 70%);
}
.hero-inner {
  display: flex; align-items: center; gap: 60px;
  position: relative; z-index: 1;
}
.hero-text { flex: 1; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 16px; border-radius: 20px;
  background: rgba(255,255,255,.2); backdrop-filter: blur(8px);
  color: #fff; font-size: 13px; font-weight: 600;
  margin-bottom: 24px;
}
.hero-badge-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #34a853;
}
.hero-title {
  font-size: 48px; font-weight: 800; color: #fff;
  line-height: 1.2; margin-bottom: 20px;
}
.hero-title .hl { color: #fbbc05; }
.hero-title .hl2 { color: #e8eaed; }
.hero-desc {
  font-size: 18px; color: rgba(255,255,255,.88);
  line-height: 1.7; margin-bottom: 32px; max-width: 520px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 32px; }
.hero-trust {
  display: flex; gap: 24px; flex-wrap: wrap;
}
.hero-trust-item {
  display: flex; align-items: center; gap: 8px;
  color: rgba(255,255,255,.8); font-size: 14px;
}
.hero-trust-item svg { width: 18px; height: 18px; flex-shrink: 0; }
.hero-visual {
  flex: 0 0 420px; position: relative;
}
.hero-frame {
  background: #fff; border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0,0,0,.2);
  overflow: hidden; animation: float 4s ease-in-out infinite;
}
.hf-bar {
  display: flex; align-items: center; gap: 6px;
  padding: 10px 14px; background: #f1f3f4;
}
.hf-dot {
  width: 10px; height: 10px; border-radius: 50%;
}
.hf-dot.r { background: #ea4335; }
.hf-dot.y { background: #fbbc05; }
.hf-dot.g { background: #34a853; }
.hf-url {
  flex: 1; margin-left: 8px;
  background: #fff; border-radius: 12px;
  padding: 4px 12px; font-size: 12px; color: #5f6368;
}
.hf-body { padding: 20px; }
.hf-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.hf-card {
  padding: 14px; border-radius: 10px;
  background: #f8f9fa; text-align: center;
}
.hf-card-ico { margin-bottom: 6px; }
.hf-card-ico svg { width: 28px; height: 28px; margin: 0 auto; }
.hf-card-lbl { font-size: 12px; color: #5f6368; font-weight: 500; }
.hf-card-val { font-size: 18px; font-weight: 700; color: #202124; }

/* --- Stats Ribbon --- */
.stats-ribbon {
  background: #fff; border-bottom: 1px solid #e8eaed;
  padding: 32px 0;
}
.stats-row {
  display: flex; justify-content: center; gap: 48px; flex-wrap: wrap;
}
.stat-item { text-align: center; min-width: 140px; }
.stat-num {
  font-size: 36px; font-weight: 800; line-height: 1.2;
}
.stat-num.c-blue { color: #4285f4; }
.stat-num.c-red { color: #ea4335; }
.stat-num.c-green { color: #34a853; }
.stat-num.c-yellow { color: #f9ab00; }
.stat-lbl { font-size: 14px; color: #5f6368; margin-top: 4px; }

/* --- Feature Cards --- */
.feat-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feat-card {
  background: #fff; border-radius: 16px;
  padding: 32px 28px; position: relative;
  border: 1px solid #e8eaed;
  transition: box-shadow .3s, transform .2s;
  overflow: hidden;
}
.feat-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0;
  height: 4px; transform: scaleX(0); transform-origin: left;
  transition: transform .3s;
}
.feat-card:hover::before { transform: scaleX(1); }
.feat-card:hover { box-shadow: 0 8px 30px rgba(0,0,0,.08); transform: translateY(-2px); }
.feat-card.fc-blue::before { background: #4285f4; }
.feat-card.fc-red::before { background: #ea4335; }
.feat-card.fc-green::before { background: #34a853; }
.feat-card.fc-yellow::before { background: #fbbc05; }
.feat-card.fc-purple::before { background: #a142f4; }
.feat-card.fc-cyan::before { background: #12b5cb; }
.feat-icon {
  width: 52px; height: 52px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px;
}
.fi-blue { background: #e8f0fe; }
.fi-red { background: #fce8e6; }
.fi-green { background: #e6f4ea; }
.fi-yellow { background: #fef7e0; }
.fi-purple { background: #f3e8fd; }
.fi-cyan { background: #e0f7fa; }
.feat-icon svg { width: 26px; height: 26px; }
.feat-name { font-size: 18px; font-weight: 700; color: #202124; margin-bottom: 10px; }
.feat-desc { font-size: 15px; color: #5f6368; line-height: 1.7; }

/* --- Deep Dive Rows --- */
.dive-row {
  display: flex; align-items: center; gap: 60px;
  margin-bottom: 64px;
}
.dive-row.rev { flex-direction: row-reverse; }
.dive-info { flex: 1; }
.dive-badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 14px; border-radius: 16px;
  font-size: 12px; font-weight: 600; margin-bottom: 16px;
}
.db-blue { background: #e8f0fe; color: #1a73e8; }
.db-red { background: #fce8e6; color: #ea4335; }
.db-green { background: #e6f4ea; color: #34a853; }
.db-yellow { background: #fef7e0; color: #f9ab00; }
.dive-title { font-size: 28px; font-weight: 700; color: #202124; margin-bottom: 14px; line-height: 1.3; }
.dive-desc { font-size: 16px; color: #5f6368; line-height: 1.7; margin-bottom: 20px; }
.dive-list { display: flex; flex-direction: column; gap: 10px; }
.dive-list-item {
  display: flex; align-items: flex-start; gap: 10px;
  font-size: 15px; color: #3c4043;
}
.dive-list-item svg { width: 20px; height: 20px; flex-shrink: 0; margin-top: 2px; }
.dive-visual { flex: 0 0 400px; }
.dive-panel {
  background: #f8f9fa; border-radius: 16px;
  padding: 28px; border: 1px solid #e8eaed;
}
.dive-panel-title { font-size: 14px; font-weight: 600; color: #5f6368; margin-bottom: 16px; }
.dive-bar-row { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.dive-bar-label { font-size: 13px; color: #5f6368; width: 80px; text-align: right; }
.dive-bar-track { flex: 1; height: 8px; background: #e8eaed; border-radius: 4px; overflow: hidden; }
.dive-bar-fill { height: 100%; border-radius: 4px; transition: width .6s; }
.dive-bar-fill.bf-blue { background: #4285f4; }
.dive-bar-fill.bf-red { background: #ea4335; }
.dive-bar-fill.bf-green { background: #34a853; }
.dive-bar-fill.bf-yellow { background: #fbbc05; }
.dive-bar-val { font-size: 13px; font-weight: 600; color: #202124; width: 40px; }
.dive-stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.dive-stat {
  background: #fff; border-radius: 10px; padding: 14px; text-align: center;
  border: 1px solid #e8eaed;
}
.dive-stat-num { font-size: 22px; font-weight: 700; }
.dive-stat-num.c-blue { color: #4285f4; }
.dive-stat-num.c-green { color: #34a853; }
.dive-stat-num.c-red { color: #ea4335; }
.dive-stat-num.c-yellow { color: #f9ab00; }
.dive-stat-lbl { font-size: 12px; color: #5f6368; margin-top: 2px; }

/* --- Platform Cards --- */
.plat-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.plat-card {
  background: #fff; border-radius: 16px;
  padding: 28px 24px; text-align: center;
  border: 1px solid #e8eaed;
  transition: box-shadow .3s, transform .2s;
}
.plat-card:hover { box-shadow: 0 8px 30px rgba(0,0,0,.08); transform: translateY(-2px); }
.plat-card.featured {
  border-color: #1a73e8; border-width: 2px;
  background: linear-gradient(180deg, #e8f0fe 0%, #fff 30%);
}
.plat-badge {
  display: inline-block; padding: 3px 12px; border-radius: 12px;
  background: #1a73e8; color: #fff; font-size: 11px; font-weight: 600;
  margin-bottom: 12px;
}
.plat-icon { margin-bottom: 16px; }
.plat-icon svg { width: 48px; height: 48px; margin: 0 auto; }
.plat-name { font-size: 18px; font-weight: 700; color: #202124; margin-bottom: 6px; }
.plat-ver { font-size: 13px; color: #5f6368; margin-bottom: 16px; }

/* --- Reviews --- */
.rev-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.rev-card {
  background: #fff; border-radius: 16px;
  padding: 28px; border: 1px solid #e8eaed;
  transition: box-shadow .3s;
}
.rev-card:hover { box-shadow: 0 6px 24px rgba(0,0,0,.06); }
.rev-top { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.rev-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 700; color: #fff;
}
.av-blue { background: #4285f4; }
.av-red { background: #ea4335; }
.av-green { background: #34a853; }
.av-yellow { background: #f9ab00; }
.av-purple { background: #a142f4; }
.av-cyan { background: #12b5cb; }
.rev-info { flex: 1; }
.rev-name { font-size: 15px; font-weight: 600; color: #202124; }
.rev-role { font-size: 12px; color: #5f6368; }
.rev-stars { margin-bottom: 10px; color: #fbbc05; font-size: 14px; letter-spacing: 2px; }
.rev-text { font-size: 15px; color: #3c4043; line-height: 1.7; }

/* --- Comparison Table --- */
.cmp-wrap { overflow-x: auto; margin: 0 auto; max-width: 900px; }
.cmp-table {
  width: 100%; border-collapse: collapse;
  background: #fff; border-radius: 12px; overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,.06);
}
.cmp-table th {
  padding: 14px 18px; background: #f8f9fa;
  font-size: 14px; font-weight: 600; color: #202124;
  text-align: center; border-bottom: 2px solid #e8eaed;
}
.cmp-table th:first-child { text-align: left; }
.cmp-table td {
  padding: 12px 18px; font-size: 14px; color: #3c4043;
  text-align: center; border-bottom: 1px solid #f1f3f4;
}
.cmp-table td:first-child { text-align: left; font-weight: 500; }
.cmp-hl { background: #e8f0fe; font-weight: 600; color: #1a73e8; }
.yes { color: #34a853; font-weight: 700; }
.no { color: #ea4335; }
.part { color: #f9ab00; }

/* --- FAQ --- */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid #e8eaed; border-radius: 12px;
  margin-bottom: 12px; overflow: hidden;
  transition: box-shadow .2s;
}
.faq-item:hover { box-shadow: 0 2px 8px rgba(0,0,0,.04); }
.faq-item.open { border-color: #1a73e8; }
.faq-q {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 24px; cursor: pointer;
  font-size: 16px; font-weight: 600; color: #202124;
  background: #fff; transition: background .2s;
}
.faq-q:hover { background: #f8f9fa; }
.faq-chevron {
  width: 20px; height: 20px; transition: transform .3s;
  flex-shrink: 0; color: #5f6368;
}
.faq-item.open .faq-chevron { transform: rotate(180deg); }
.faq-a {
  max-height: 0; overflow: hidden; transition: max-height .3s;
}
.faq-a-inner {
  padding: 0 24px 20px;
  font-size: 15px; color: #5f6368; line-height: 1.7;
}

/* --- CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, #4285f4 0%, #5e97f6 50%, #7b9ff7 100%);
  padding: 64px 0; text-align: center;
  position: relative; overflow: hidden;
}
.cta-banner::before {
  content: ''; position: absolute; top: -100px; right: -100px;
  width: 300px; height: 300px; border-radius: 50%;
  background: radial-gradient(circle, rgba(251,188,5,.2) 0%, transparent 70%);
}
.cta-title {
  font-size: 32px; font-weight: 700; color: #fff;
  margin-bottom: 14px; position: relative;
}
.cta-desc {
  font-size: 17px; color: rgba(255,255,255,.85);
  margin-bottom: 28px; position: relative;
}
.cta-actions { position: relative; display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

/* --- Download Hero --- */
.dl-hero {
  background: linear-gradient(160deg, #4285f4 0%, #5e97f6 40%, #a8c7fa 100%);
  padding: 72px 0 56px; text-align: center;
}
.dl-hero-tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 16px; border-radius: 20px;
  background: rgba(255,255,255,.2); backdrop-filter: blur(8px);
  color: #fff; font-size: 13px; font-weight: 600;
  margin-bottom: 20px;
}
.dl-hero-title { font-size: 40px; font-weight: 800; color: #fff; margin-bottom: 12px; }
.dl-hero-sub { font-size: 17px; color: rgba(255,255,255,.85); margin-bottom: 0; }

/* --- Download Main Card --- */
.dl-main {
  max-width: 640px; margin: -40px auto 0; position: relative; z-index: 2;
}
.dl-card {
  background: #fff; border-radius: 20px;
  box-shadow: 0 12px 48px rgba(0,0,0,.12);
  padding: 36px; text-align: center;
  border: 1px solid #e8eaed;
}
.dl-card-head {
  display: flex; align-items: center; justify-content: center; gap: 14px;
  margin-bottom: 20px;
}
.dl-card-icon svg { width: 56px; height: 56px; }
.dl-card-info { text-align: left; }
.dl-card-name { font-size: 22px; font-weight: 700; color: #202124; }
.dl-card-meta { font-size: 13px; color: #5f6368; }
.dl-specs {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 12px; margin-bottom: 20px;
}
.dl-spec {
  background: #f8f9fa; border-radius: 10px; padding: 12px;
}
.dl-spec-label { font-size: 12px; color: #5f6368; margin-bottom: 4px; }
.dl-spec-val { font-size: 15px; font-weight: 600; color: #202124; }
.dl-sec-badge {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px; border-radius: 8px;
  background: #e6f4ea; color: #34a853;
  font-size: 13px; font-weight: 600;
  margin-bottom: 20px;
}
.dl-card-btns { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }

/* --- Other Platforms --- */
.op-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.op-card {
  background: #fff; border-radius: 16px;
  padding: 28px; text-align: center;
  border: 1px solid #e8eaed;
  transition: box-shadow .3s;
}
.op-card:hover { box-shadow: 0 6px 24px rgba(0,0,0,.06); }
.op-icon svg { width: 44px; height: 44px; margin: 0 auto 14px; }
.op-name { font-size: 17px; font-weight: 700; color: #202124; margin-bottom: 4px; }
.op-ver { font-size: 13px; color: #5f6368; margin-bottom: 12px; }
.op-steps { text-align: left; margin-top: 14px; }
.op-step {
  display: flex; align-items: flex-start; gap: 8px;
  font-size: 13px; color: #5f6368; margin-bottom: 6px;
}
.op-step-num {
  width: 20px; height: 20px; border-radius: 50%;
  background: #e8f0fe; color: #1a73e8;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 700; flex-shrink: 0;
}

/* --- Install Guide --- */
.guide-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.guide-col-title {
  font-size: 20px; font-weight: 700; color: #202124;
  margin-bottom: 20px; display: flex; align-items: center; gap: 8px;
}
.guide-col-title .dot {
  width: 10px; height: 10px; border-radius: 50%;
}
.dot-blue { background: #4285f4; }
.dot-green { background: #34a853; }
.guide-steps { display: flex; flex-direction: column; gap: 16px; }
.gstep {
  display: flex; gap: 16px; align-items: flex-start;
}
.gstep-num {
  width: 36px; height: 36px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700; color: #fff; flex-shrink: 0;
}
.gstep-num.gn-blue { background: #4285f4; }
.gstep-num.gn-green { background: #34a853; }
.gstep-body { flex: 1; }
.gstep-title { font-size: 16px; font-weight: 600; color: #202124; margin-bottom: 4px; }
.gstep-desc { font-size: 14px; color: #5f6368; line-height: 1.6; }

/* --- System Requirements --- */
.req-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.req-card {
  background: #fff; border-radius: 14px;
  padding: 24px; border: 1px solid #e8eaed;
}
.req-icon { margin-bottom: 12px; }
.req-icon svg { width: 32px; height: 32px; }
.req-title { font-size: 16px; font-weight: 700; color: #202124; margin-bottom: 8px; }
.req-val { font-size: 14px; color: #5f6368; line-height: 1.6; }

/* --- Version Log --- */
.ver-list { max-width: 700px; margin: 0 auto; }
.ver-item {
  display: flex; gap: 16px; margin-bottom: 24px;
}
.ver-dot-col { display: flex; flex-direction: column; align-items: center; }
.ver-dot {
  width: 14px; height: 14px; border-radius: 50%;
  flex-shrink: 0;
}
.vd-blue { background: #4285f4; }
.vd-green { background: #34a853; }
.vd-yellow { background: #fbbc05; }
.vd-red { background: #ea4335; }
.vd-purple { background: #a142f4; }
.ver-line { width: 2px; flex: 1; background: #e8eaed; min-height: 20px; }
.ver-body { flex: 1; }
.ver-head { display: flex; align-items: center; gap: 10px; margin-bottom: 4px; }
.ver-num { font-size: 16px; font-weight: 700; color: #202124; }
.ver-tag {
  padding: 2px 10px; border-radius: 10px;
  font-size: 11px; font-weight: 600;
}
.vt-stable { background: #e6f4ea; color: #34a853; }
.vt-lts { background: #e8f0fe; color: #1a73e8; }
.vt-beta { background: #fef7e0; color: #f9ab00; }
.ver-date { font-size: 13px; color: #5f6368; }
.ver-desc { font-size: 14px; color: #5f6368; line-height: 1.6; }

/* --- Security Banner --- */
.sec-banner {
  display: flex; align-items: center; gap: 16px;
  background: #e6f4ea; border-radius: 14px;
  padding: 24px 28px;
}
.sec-banner-icon svg { width: 40px; height: 40px; flex-shrink: 0; color: #34a853; }
.sec-banner-text { flex: 1; }
.sec-banner-title { font-size: 16px; font-weight: 700; color: #202124; margin-bottom: 4px; }
.sec-banner-desc { font-size: 14px; color: #3c4043; line-height: 1.6; }

/* --- Article Hero --- */
.art-hero {
  background: linear-gradient(160deg, #4285f4 0%, #5e97f6 50%, #a8c7fa 100%);
  padding: 80px 0 60px; text-align: center;
}
.art-hero-title { font-size: 40px; font-weight: 800; color: #fff; margin-bottom: 12px; }
.art-hero-sub { font-size: 17px; color: rgba(255,255,255,.85); margin-bottom: 24px; }
.kw-strip {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 8px;
}
.kw {
  padding: 5px 14px; border-radius: 16px;
  background: rgba(255,255,255,.2); backdrop-filter: blur(6px);
  color: #fff; font-size: 13px; font-weight: 500;
}

/* --- Article Layout --- */
.art-layout {
  display: flex; gap: 40px;
  max-width: 1200px; margin: 0 auto; padding: 60px 24px;
}
.art-body { flex: 1; min-width: 0; }
.art-body h2 {
  font-size: 24px; font-weight: 700; color: #202124;
  margin: 40px 0 16px; padding-bottom: 10px;
  border-bottom: 2px solid #e8eaed;
  scroll-margin-top: 80px;
}
.art-body h2:first-child { margin-top: 0; }
.art-body h3 {
  font-size: 18px; font-weight: 600; color: #202124;
  margin: 24px 0 10px;
}
.art-body p {
  font-size: 16px; color: #3c4043; line-height: 1.8;
  margin-bottom: 16px;
}
.art-body ul, .art-body ol {
  margin: 12px 0 16px 20px;
}
.art-body li {
  font-size: 15px; color: #3c4043; line-height: 1.7;
  margin-bottom: 6px;
}
.art-body strong { color: #202124; }

/* --- Inline CTA --- */
.inline-cta {
  background: linear-gradient(135deg, #e8f0fe 0%, #f8f9fa 100%);
  border-radius: 14px; padding: 28px;
  margin: 32px 0; border: 1px solid #d2e3fc;
}
.inline-cta-title { font-size: 18px; font-weight: 700; color: #1a73e8; margin-bottom: 8px; }
.inline-cta-desc { font-size: 15px; color: #5f6368; margin-bottom: 16px; }

/* --- Tips Grid --- */
.tips-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 16px; margin: 16px 0;
}
.tip-card {
  background: #f8f9fa; border-radius: 10px;
  padding: 16px; border: 1px solid #e8eaed;
}
.tip-num {
  width: 24px; height: 24px; border-radius: 50%;
  background: #1a73e8; color: #fff;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 700; margin-bottom: 8px;
}
.tip-title { font-size: 14px; font-weight: 600; color: #202124; margin-bottom: 4px; }
.tip-desc { font-size: 13px; color: #5f6368; line-height: 1.5; }

/* --- Sidebar --- */
.sidebar { flex: 0 0 300px; }
.sbox {
  background: #fff; border-radius: 14px;
  padding: 24px; border: 1px solid #e8eaed;
  margin-bottom: 20px;
}
.sbox-title {
  font-size: 16px; font-weight: 700; color: #202124;
  margin-bottom: 16px; padding-bottom: 10px;
  border-bottom: 2px solid #e8eaed;
}
.sdl-btn {
  display: flex; align-items: center; gap: 10px;
  width: 100%; padding: 12px 16px; border-radius: 10px;
  border: 1px solid #e8eaed; background: #fff;
  cursor: pointer; transition: background .2s, border-color .2s;
  margin-bottom: 10px; text-align: left; font-size: 14px;
}
.sdl-btn:hover { background: #e8f0fe; border-color: #d2e3fc; }
.sdl-btn.primary { background: #1a73e8; color: #fff; border-color: #1a73e8; }
.sdl-btn.primary:hover { background: #1557b0; }
.sdl-btn svg { width: 22px; height: 22px; flex-shrink: 0; }
.stoc { margin-bottom: 0; }
.stoc a {
  display: block; padding: 6px 0; font-size: 14px; color: #5f6368;
  border-bottom: 1px solid #f1f3f4; transition: color .2s;
}
.stoc a:hover { color: #1a73e8; }
.sstat { display: flex; flex-direction: column; gap: 12px; }
.sstat-item { display: flex; justify-content: space-between; align-items: center; }
.sstat-num { font-size: 20px; font-weight: 700; color: #1a73e8; }
.sstat-lbl { font-size: 13px; color: #5f6368; }
.side-security {
  background: #e6f4ea; border-radius: 10px;
  padding: 16px; display: flex; align-items: flex-start; gap: 10px;
}
.side-security svg { width: 20px; height: 20px; color: #34a853; flex-shrink: 0; margin-top: 2px; }
.side-security p { font-size: 13px; color: #34a853; line-height: 1.5; }

/* --- Footer --- */
.site-footer {
  background: #202124; color: #e8eaed;
  padding: 40px 0 28px;
}
.footer-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; justify-content: space-between; align-items: flex-start;
  flex-wrap: wrap; gap: 20px;
}
.footer-brand {
  font-size: 18px; font-weight: 700; color: #fff;
  margin-bottom: 8px;
}
.footer-security {
  font-size: 14px; color: #34a853; margin-bottom: 6px;
}
.footer-note {
  font-size: 13px; color: #9aa0a6; line-height: 1.6;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero-inner { flex-direction: column; gap: 40px; }
  .hero-visual { flex: 0 0 auto; max-width: 360px; }
  .dive-row, .dive-row.rev { flex-direction: column; gap: 32px; }
  .dive-visual { flex: 0 0 auto; width: 100%; max-width: 400px; }
  .guide-grid { grid-template-columns: 1fr; }
  .art-layout { flex-direction: column; }
  .sidebar { flex: 0 0 auto; width: 100%; }
  .req-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .hero { padding: 72px 0 56px; }
  .hero-title { font-size: 32px; }
  .hero-desc { font-size: 16px; }
  .feat-grid { grid-template-columns: 1fr; }
  .plat-grid { grid-template-columns: repeat(2, 1fr); }
  .rev-grid { grid-template-columns: 1fr; }
  .op-grid { grid-template-columns: 1fr; }
  .dl-specs { grid-template-columns: repeat(2, 1fr); }
  .stats-row { gap: 24px; }
  .stat-num { font-size: 28px; }
  .sec-title { font-size: 28px; }
  .sec { padding: 56px 0; }
  .dl-hero-title { font-size: 30px; }
  .cta-title { font-size: 26px; }
  .art-hero-title { font-size: 30px; }
  .tips-grid { grid-template-columns: 1fr; }
  .nav-list { display: none; }
  .nav-mob-btn { display: flex; }
  .req-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .hero-title { font-size: 26px; }
  .hero-visual { max-width: 280px; }
  .plat-grid { grid-template-columns: 1fr; }
  .dl-specs { grid-template-columns: 1fr; }
  .stats-row { gap: 16px; }
  .hero-actions { flex-direction: column; }
  .cta-actions { flex-direction: column; align-items: center; }
}