/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 40px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--radius-btn);
  font-size: 15px;
  font-weight: 500;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease), box-shadow 0.2s var(--ease), transform 0.2s var(--ease);
}

.btn-lg { height: 48px; padding: 0 28px; font-size: 16px; }
.btn-sm { height: 32px; padding: 0 14px; font-size: 13px; }

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-primary);
}

.btn-outline {
  background: var(--color-surface);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary-muted);
  color: var(--color-primary-dark);
}

.btn-outline-light {
  background: transparent;
  color: var(--color-text-inverse);
  border-color: rgba(255, 255, 255, 0.7);
}

.btn-outline-light:hover {
  background: rgba(255, 255, 255, 0.12);
  color: var(--color-text-inverse);
  border-color: var(--color-text-inverse);
}

.cta-band .btn-primary {
  background: var(--color-surface);
  color: var(--color-primary);
}

.cta-band .btn-primary:hover { background: var(--color-primary-muted); color: var(--color-primary-dark); }

.btn svg { width: 16px; height: 16px; }

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-weight: 500;
  font-size: 15px;
}

.text-link::after { content: "→"; transition: transform 0.2s var(--ease); }
.text-link:hover::after { transform: translateX(3px); }

.ext-link::after { content: "↗"; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background: var(--gradient-hero);
  padding: 72px 0 88px;
  border-bottom: 1px solid rgba(17, 127, 255, 0.14);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-primary-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-primary-subtle) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 70% 40%, #000 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at 70% 40%, #000 0%, transparent 70%);
  opacity: 0.9;
  pointer-events: none;
}

/* 底部柔和落差，和下方内容区拉开层次 */
.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 56px;
  background: linear-gradient(180deg, transparent 0%, rgba(15, 23, 42, 0.045) 100%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  align-items: center;
  gap: 48px;
}

.hero-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  border: 1px solid var(--color-primary-subtle);
  color: var(--color-primary);
  font-size: 14px;
  font-weight: 600;
}

.hero h1 {
  font-size: clamp(32px, 4.4vw, 52px);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero h1 em {
  font-style: normal;
  color: var(--color-primary);
}

.hero-lead {
  font-size: var(--fs-lg);
  color: var(--color-text-muted);
  max-width: 560px;
  margin-bottom: 32px;
}

.hero-visual img {
  width: 100%;
  max-width: 560px;
  margin-left: auto;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.page-hero {
  position: relative;
  overflow: hidden;
  background: var(--gradient-hero);
  padding: 40px 0 64px;
  border-bottom: 1px solid rgba(17, 127, 255, 0.12);
}

.page-hero .container { position: relative; }

.page-hero h1 { margin-bottom: 12px; }

.page-hero .lead {
  max-width: 760px;
  font-size: var(--fs-lg);
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.page-hero-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 48px;
  align-items: center;
}

.page-hero-visual img {
  max-width: 400px;
  margin-left: auto;
}

@media (max-width: 900px) {
  .hero { padding: 48px 0 64px; }
  .hero-grid,
  .page-hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-visual img { max-width: 420px; margin: 0 auto; }
  .page-hero-visual { display: none; }
}

/* ---------- Grids & cards ---------- */
.grid {
  display: grid;
  gap: var(--gap);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 { grid-template-columns: 1fr; }
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 28px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), border-color 0.25s var(--ease);
}

a.card { color: inherit; }

.card:hover,
a.card:focus-visible {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-subtle);
}

.card h3 { margin-bottom: 8px; }

.card p {
  color: var(--color-text-muted);
  font-size: 15px;
}

.card .text-link { margin-top: auto; padding-top: 8px; color: var(--color-primary); }
a.card:hover .text-link { color: var(--color-primary-dark); }
a.card:hover .text-link::after { transform: translateX(3px); }

.card-icon {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-muted);
  color: var(--color-primary);
}

.card-icon svg { width: 26px; height: 26px; }

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
}

.card-head h3 { margin: 0; }

.card-kicker {
  font-size: 13px;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 4px;
}

.badge {
  display: inline-flex;
  align-items: center;
  height: 22px;
  padding: 0 8px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  background: var(--color-accent-muted);
  color: var(--color-accent);
  white-space: nowrap;
}

.badge-blue {
  background: var(--color-primary-muted);
  color: var(--color-primary);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 4px 0 16px;
}

.tag-list li {
  padding: 2px 10px;
  border-radius: var(--radius-btn);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 13px;
  color: var(--color-text-muted);
}

.tag-list-center {
  justify-content: center;
  margin-bottom: 32px;
}

.tag-list-center li {
  padding: 6px 16px;
  font-size: 15px;
  background: var(--color-surface);
  color: var(--color-primary);
  border-color: var(--color-primary-subtle);
}

/* ---------- Check list ---------- */
.check-list {
  list-style: none;
  display: grid;
  gap: 10px;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  color: var(--color-text);
  font-size: 15px;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary-muted);
}

.check-list li::after {
  content: "";
  position: absolute;
  left: 6px;
  top: 9px;
  width: 6px;
  height: 9px;
  border-right: 2px solid var(--color-primary);
  border-bottom: 2px solid var(--color-primary);
  transform: rotate(45deg);
}

.check-list.cols-2 { grid-template-columns: repeat(2, 1fr); gap: 10px 24px; }

@media (max-width: 768px) {
  .check-list.cols-2 { grid-template-columns: 1fr; }
}

/* ---------- Stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.stat {
  padding: 28px 24px;
  background: var(--color-surface);
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 32px;
  font-weight: 800;
  line-height: 1.2;
  color: var(--color-primary);
}

.stat-value small { font-size: 16px; font-weight: 600; margin-left: 2px; }

.stat-label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  color: var(--color-text-muted);
}

.stats-note {
  margin-top: 12px;
  font-size: 13px;
  color: var(--color-text-muted);
  text-align: center;
}

/* ---------- Steps ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--gap);
  list-style: none;
  counter-reset: step;
}

.step {
  position: relative;
  padding: 28px 24px 24px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  counter-increment: step;
}

.step::before {
  content: counter(step);
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  margin-bottom: 16px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-weight: 700;
  font-size: 15px;
}

.step h3 { font-size: 17px; margin-bottom: 6px; }
.step p { margin: 0; font-size: 14px; color: var(--color-text-muted); }

/* ---------- Fact box (GEO) ---------- */
.fact-box {
  padding: 28px 32px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius);
}

.fact-box h2 {
  font-size: 18px;
  margin-bottom: 16px;
}

.fact-list {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 10px 20px;
  margin: 0;
  font-size: 15px;
}

.fact-list dt { color: var(--color-text-muted); }
.fact-list dd { margin: 0; color: var(--color-text); }

@media (max-width: 640px) {
  .fact-list { grid-template-columns: 1fr; gap: 2px; }
  .fact-list dd { margin-bottom: 10px; }
}

/* ---------- Split ---------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.split-text p { color: var(--color-text-muted); }

.panel {
  padding: 32px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
}

@media (max-width: 900px) {
  .split { grid-template-columns: 1fr; gap: 32px; }
}

/* ---------- Architecture diagram ---------- */
.arch {
  display: grid;
  gap: 12px;
}

.arch-layer {
  display: grid;
  grid-template-columns: 160px 1fr;
  align-items: stretch;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.arch-name {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 16px 20px;
  background: var(--color-primary-muted);
  color: var(--color-primary);
  font-weight: 700;
}

.arch-name small {
  font-weight: 400;
  font-size: 12px;
  color: var(--color-text-muted);
}

.arch-items {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 16px;
  list-style: none;
}

.arch-items li a,
.arch-items li span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
}

.arch-items li a {
  border-color: var(--color-primary-subtle);
  background: var(--color-surface);
  color: var(--color-primary);
  font-weight: 600;
}

.arch-items li a:hover { background: var(--color-primary-muted); }

.arch-layer.is-strong .arch-name {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.arch-layer.is-strong .arch-name small { color: rgba(255, 255, 255, 0.8); }

@media (max-width: 640px) {
  .arch-layer { grid-template-columns: 1fr; }
}

/* ---------- Flow (horizontal chain) ---------- */
.flow {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  gap: 12px;
  list-style: none;
}

.flow li {
  position: relative;
  flex: 1 1 140px;
  padding: 18px 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  text-align: center;
  font-size: 14px;
  color: var(--color-text-muted);
}

.flow li strong {
  display: block;
  color: var(--color-text);
  font-size: 16px;
  margin-bottom: 4px;
}

.flow li:not(:last-child)::after {
  content: "";
  position: absolute;
  right: -10px;
  top: 50%;
  z-index: 1;
  width: 8px;
  height: 8px;
  margin-top: -4px;
  border-top: 2px solid var(--color-primary-light);
  border-right: 2px solid var(--color-primary-light);
  transform: rotate(45deg);
}

.flow-vertical { flex-direction: column; gap: 20px; }
.flow-vertical li { flex: none; }

.flow-vertical li:not(:last-child)::after {
  right: auto;
  left: 50%;
  top: auto;
  bottom: -14px;
  margin: 0 0 0 -4px;
  transform: rotate(135deg);
}

@media (max-width: 640px) {
  .flow:not(.flow-vertical) { flex-direction: column; gap: 20px; }
  .flow:not(.flow-vertical) li:not(:last-child)::after {
    right: auto;
    left: 50%;
    top: auto;
    bottom: -14px;
    margin: 0 0 0 -4px;
    transform: rotate(135deg);
  }
}

/* ---------- External product block ---------- */
.ext-block {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px 36px;
  border-radius: var(--radius);
  background: var(--color-surface);
  border: 1px solid var(--color-primary-subtle);
  box-shadow: var(--shadow-md);
}

.ext-block h2 { font-size: 22px; margin-bottom: 4px; }
.ext-block p { margin: 0; color: var(--color-text-muted); }
.ext-url { font-size: 14px; color: var(--color-primary); }

@media (max-width: 768px) {
  .ext-block { flex-direction: column; align-items: flex-start; padding: 24px; }
}

/* ---------- FAQ ---------- */
.faq-list { display: grid; gap: 12px; }

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-item summary {
  position: relative;
  padding: 18px 56px 18px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 22px;
  font-weight: 400;
  color: var(--color-primary);
}

.faq-item[open] summary::after { content: "−"; }
.faq-item[open] summary { color: var(--color-primary); }

.faq-answer {
  padding: 0 24px 20px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.faq-answer p { margin: 0; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--gradient-band);
  color: var(--color-text-inverse);
  padding: 56px 0;
}

.cta-band-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.cta-band h2 { color: var(--color-text-inverse); font-size: 28px; margin-bottom: 8px; }
.cta-band p { margin: 0; opacity: 0.9; }

.cta-band-actions {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 14px;
}

.cta-band-buttons { display: flex; flex-wrap: wrap; gap: 12px; }

.cta-band-links {
  display: flex;
  gap: 20px;
  font-size: 14px;
}

.cta-band-links a { color: rgba(255, 255, 255, 0.85); }
.cta-band-links a:hover { color: var(--color-text-inverse); text-decoration: underline; }

@media (max-width: 900px) {
  .cta-band-inner { flex-direction: column; align-items: flex-start; }
  .cta-band-actions { align-items: flex-start; }
}

/* ---------- Scene card (image header) ---------- */
.scene-card {
  overflow: hidden;
  padding: 0;
}

.scene-media {
  display: grid;
  place-items: center;
  height: 140px;
  background: linear-gradient(135deg, var(--color-primary-muted), var(--color-primary-subtle));
  color: var(--color-primary);
}

.scene-media svg { width: 56px; height: 56px; }
.scene-body { padding: 24px 28px 28px; display: flex; flex-direction: column; flex: 1; }

.mt-24 { margin-top: 24px; }

/* ---------- Reveal on scroll ---------- */
.js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

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

@media (prefers-reduced-motion: reduce) {
  .js .reveal { opacity: 1; transform: none; }
  .hero-visual img { animation: none; }
}