:root {
  --bg: #060b14;
  --bg-card: #111827;
  --bg-elevated: #1a2332;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --accent: #22c55e;
  --accent-2: #8b5cf6;
  --border: rgba(148, 163, 184, 0.15);
  --radius: 16px;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
  --max: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

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

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

.container {
  width: min(100% - 40px, var(--max));
  margin: 0 auto;
}

/* —— Nav —— */
.site-nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(6, 11, 20, 0.82);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 18px;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary), var(--accent-2));
  font-size: 13px;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 14px;
  color: var(--muted);
}

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

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff !important;
  font-weight: 600;
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35);
}

.menu-btn {
  display: none;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  border-radius: 10px;
  padding: 8px 12px;
}

/* —— Hero —— */
.hero {
  position: relative;
  padding: 120px 0 80px;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 55% at 50% -10%, rgba(59, 130, 246, 0.28), transparent),
    radial-gradient(ellipse 50% 40% at 90% 20%, rgba(139, 92, 246, 0.15), transparent),
    radial-gradient(ellipse 40% 35% at 10% 80%, rgba(34, 197, 94, 0.1), transparent);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 20px;
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(34px, 5vw, 52px);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero h1 span {
  background: linear-gradient(135deg, #93c5fd, #c4b5fd);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-lead {
  margin: 0 0 28px;
  font-size: 18px;
  color: var(--muted);
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 36px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  box-shadow: 0 12px 32px rgba(37, 99, 235, 0.35);
}

.btn-ghost {
  border-color: var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.stat {
  padding: 16px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}

.stat strong {
  display: block;
  font-size: 28px;
  line-height: 1.1;
  margin-bottom: 4px;
}

.stat span {
  font-size: 13px;
  color: var(--muted);
}

.hero-panel {
  border-radius: 24px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(26, 35, 50, 0.95), rgba(17, 24, 39, 0.95));
  box-shadow: var(--shadow);
  overflow: hidden;
}

.panel-top {
  display: flex;
  gap: 8px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.2);
}

.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-r { background: #ef4444; }
.dot-y { background: #f59e0b; }
.dot-g { background: #22c55e; }

.demo-box { padding: 24px; }

.demo-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
}

.demo-card {
  padding: 16px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  min-height: 88px;
}

.demo-label {
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 8px;
}

.demo-text { font-size: 15px; line-height: 1.5; }

.demo-text.live {
  color: #86efac;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.72; }
}

.demo-status {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px rgba(34, 197, 94, 0.8);
}

/* —— Sections —— */
section { padding: 88px 0; }

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 48px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4vw, 38px);
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.card {
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
  border-color: rgba(59, 130, 246, 0.35);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-size: 22px;
  margin-bottom: 16px;
  background: rgba(59, 130, 246, 0.12);
}

.card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.tag {
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--muted);
}

/* —— Flow —— */
.flow {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  position: relative;
}

.flow-step {
  text-align: center;
  padding: 28px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.flow-num {
  width: 36px;
  height: 36px;
  margin: 0 auto 14px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary), var(--accent-2));
  font-weight: 700;
}

/* —— FAQ —— */
.faq { max-width: 760px; margin: 0 auto; }

.faq-item {
  border: 1px solid var(--border);
  border-radius: 14px;
  margin-bottom: 12px;
  overflow: hidden;
  background: var(--bg-card);
}

.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  border: 0;
  background: transparent;
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}

.faq-a {
  display: none;
  padding: 0 20px 18px;
  color: var(--muted);
  font-size: 14px;
}

.faq-item.open .faq-a { display: block; }
.faq-item.open .faq-q span:last-child { transform: rotate(45deg); }

/* —— CTA band —— */
.cta-band {
  margin: 0 20px 88px;
  border-radius: 24px;
  padding: 56px 32px;
  text-align: center;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.25), rgba(139, 92, 246, 0.18));
  border: 1px solid rgba(59, 130, 246, 0.25);
}

.cta-band h2 { margin: 0 0 12px; font-size: 32px; }
.cta-band p { margin: 0 0 24px; color: var(--muted); }

/* —— Footer —— */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  color: var(--muted);
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-grid h4 {
  margin: 0 0 12px;
  color: var(--text);
  font-size: 15px;
}

.footer-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-grid li { margin-bottom: 8px; }
.footer-grid a:hover { color: var(--text); }

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 13px;
}

/* —— Download page —— */
.download-hero {
  padding: 110px 0 60px;
  text-align: center;
}

.download-card {
  max-width: 520px;
  margin: 32px auto 0;
  padding: 40px;
  border-radius: 24px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow);
}

.download-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
  color: var(--muted);
  font-size: 14px;
}

.download-summary {
  margin: 0 0 24px;
  color: var(--primary);
  font-size: 13px;
  line-height: 1.6;
}

.changelog-section {
  max-width: 640px;
  margin: 40px auto 0;
  text-align: left;
}

.changelog-panel {
  padding: 28px 32px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow);
}

.changelog-panel h2 {
  margin: 0 0 8px;
  font-size: 20px;
}

.changelog-summary {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.changelog-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.changelog-item {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.02);
  overflow: hidden;
}

.changelog-item summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  user-select: none;
}

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

.changelog-item summary::after {
  content: '›';
  margin-left: auto;
  color: var(--muted);
  transform: rotate(90deg);
  transition: transform 0.2s ease;
}

.changelog-item[open] summary::after {
  transform: rotate(-90deg);
}

.changelog-version {
  color: var(--primary);
  font-size: 15px;
}

.changelog-item time {
  color: var(--muted);
  font-size: 13px;
  font-weight: 400;
}

.changelog-item ul {
  margin: 0;
  padding: 0 16px 16px 36px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.85;
}

.changelog-item li + li {
  margin-top: 4px;
}

.changelog-empty {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.wechat-tip {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.88);
  color: #fff;
  padding: 24px;
  text-align: center;
  font-size: 16px;
}

.hero-note {
  margin: 12px 0 0;
  font-size: 12px;
  color: var(--muted);
}

.section-alt {
  background: rgba(255, 255, 255, 0.02);
}

/* —— Architecture —— */
.arch-flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 12px 8px;
  align-items: stretch;
  margin-bottom: 32px;
}

.arch-node {
  padding: 24px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  text-align: center;
}

.arch-node-highlight {
  border-color: rgba(59, 130, 246, 0.45);
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.1), var(--bg-card));
}

.arch-node-wide {
  grid-column: 1 / -1;
  text-align: left;
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.arch-node-wide .arch-icon { flex-shrink: 0; }

.arch-icon {
  font-size: 32px;
  margin-bottom: 10px;
}

.arch-node h3 {
  margin: 0 0 8px;
  font-size: 17px;
}

.arch-node p {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.65;
}

.arch-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 22px;
  font-weight: 700;
}

.spec-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.spec-item {
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}

.spec-item span {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 4px;
}

.spec-item strong {
  font-size: 14px;
  font-weight: 600;
}

/* —— Roles —— */
.role-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.role-card {
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.role-venue { border-top: 3px solid var(--primary); }
.role-interpreter { border-top: 3px solid var(--accent-2); }

.role-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 12px;
  background: rgba(59, 130, 246, 0.15);
  color: #93c5fd;
}

.role-interpreter .role-badge {
  background: rgba(139, 92, 246, 0.15);
  color: #c4b5fd;
}

.role-card h3 {
  margin: 0 0 16px;
  font-size: 20px;
}

.role-list {
  margin: 0 0 16px;
  padding-left: 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.85;
}

.role-tip {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
  font-style: italic;
}

/* —— Subtitles —— */
.subtitle-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 24px;
}

.subtitle-card {
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.subtitle-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.subtitle-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.steps-panel {
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.steps-panel h3 {
  margin: 0 0 16px;
  font-size: 18px;
}

.steps-list {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.9;
}

.steps-list code {
  padding: 2px 6px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.06);
  font-size: 13px;
}

/* —— Membership preview —— */
.membership-preview {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 20px;
}

.membership-card {
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.membership-card.featured {
  border-color: rgba(59, 130, 246, 0.45);
  box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.12);
}

.membership-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.membership-card h3 {
  margin: 0 0 14px;
  font-size: 20px;
}

.membership-card ul {
  margin: 0 0 18px;
  padding-left: 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.membership-prices {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.membership-prices span {
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: #93c5fd;
  font-weight: 600;
}

.membership-note {
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  margin: 0 0 24px;
}

.section-cta {
  text-align: center;
}

.flow-5 {
  grid-template-columns: repeat(5, 1fr);
}

.flow-link {
  margin-top: 12px;
  margin-bottom: 0;
}

.flow-link a {
  color: var(--primary);
  font-size: 14px;
}

.scene-card p {
  line-height: 1.7;
}

.req-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.req-card {
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.req-card h3 {
  margin: 0 0 14px;
  font-size: 17px;
}

.req-card ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.85;
}

.faq-a code {
  padding: 2px 6px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.06);
  font-size: 13px;
}

.faq-a a {
  color: var(--primary);
}

/* —— Responsive —— */
@media (max-width: 960px) {
  .hero-grid,
  .grid-3,
  .grid-4,
  .flow,
  .flow-5,
  .footer-grid,
  .role-split,
  .subtitle-grid,
  .membership-preview,
  .spec-grid,
  .req-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: 1fr 1fr; }
  .arch-flow {
    grid-template-columns: 1fr;
  }
  .arch-arrow { transform: rotate(90deg); padding: 4px 0; }
  .arch-node-wide { flex-direction: column; }
}

@media (max-width: 720px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    padding: 16px 20px 20px;
    background: rgba(6, 11, 20, 0.98);
    border-bottom: 1px solid var(--border);
  }
  .menu-btn { display: inline-flex; }
  .hero-grid,
  .grid-3,
  .grid-4,
  .flow,
  .flow-5,
  .footer-grid,
  .role-split,
  .subtitle-grid,
  .membership-preview,
  .spec-grid,
  .req-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 96px; }
  .demo-row { grid-template-columns: 1fr; }
}