/* ============================================
   爱云发科技 - 统一设计系统
   Design System v2.0
   ============================================ */

/* ----- CSS Variables ----- */
:root {
  --bg-primary: #0f0f23;
  --bg-secondary: #1a1a3e;
  --bg-card: #161b22;
  --bg-card-hover: #1c2030;
  --accent-cyan: #00d4ff;
  --accent-purple: #764ba2;
  --gradient: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  --gradient-h: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  --text-primary: #ffffff;
  --text-secondary: rgba(255,255,255,0.72);
  --text-muted: rgba(255,255,255,0.45);
  --border-subtle: rgba(255,255,255,0.06);
  --border-card: rgba(255,255,255,0.08);
  --border-accent: rgba(0,212,255,0.2);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-md: 0 8px 30px rgba(0,0,0,0.4);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
  --shadow-cyan: 0 10px 40px rgba(0,212,255,0.25);
  --header-height: 64px;
  --container-max: 1200px;
  --section-gap: 100px;
}

/* ----- Reset & Base ----- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--header-height); }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }

/* ----- Typography ----- */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.25; }
h1 { font-size: clamp(2.2rem, 5vw, 3.8rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.5rem); }
h3 { font-size: 1.25rem; }
.text-gradient {
  background: linear-gradient(135deg, #fff 0%, var(--accent-cyan) 50%, var(--accent-purple) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.text-cyan { color: var(--accent-cyan); }
.text-muted { color: var(--text-muted); }

/* ----- Container ----- */
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 24px; }
.section { padding: var(--section-gap) 24px; }

/* ----- Header & Navigation ----- */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(15,15,35,0.95); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  height: var(--header-height);
}
.header-inner {
  max-width: var(--container-max); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; padding: 0 24px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.1rem; }
.logo img { height: 34px; border-radius: 6px; }
.logo .sub { font-size: 0.65rem; color: var(--text-muted); font-weight: 400; white-space: nowrap; margin-left: 4px; }

.nav-desktop { display: flex; gap: 4px; }
.nav-desktop a {
  color: var(--text-secondary); font-size: 0.9rem;
  padding: 8px 14px; border-radius: var(--radius-sm);
  transition: all 0.25s;
}
.nav-desktop a:hover, .nav-desktop a.active {
  color: var(--accent-cyan); background: rgba(0,212,255,0.08);
}

.menu-toggle {
  display: none; background: none; border: none; color: #fff;
  font-size: 1.5rem; cursor: pointer; padding: 8px; border-radius: var(--radius-sm);
  line-height: 1; transition: background 0.2s;
}
.menu-toggle:hover { background: rgba(255,255,255,0.08); }

.nav-mobile {
  display: none; position: fixed; top: var(--header-height); left: 0; right: 0;
  background: rgba(15,15,35,0.98); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 12px 20px; z-index: 999; flex-direction: column; gap: 2px;
}
.nav-mobile.open { display: flex; }
.nav-mobile a {
  color: var(--text-secondary); font-size: 1rem;
  padding: 12px 16px; border-radius: 10px; transition: all 0.25s;
}
.nav-mobile a:hover, .nav-mobile a.active {
  color: var(--accent-cyan); background: rgba(0,212,255,0.08);
}

/* ----- Page Hero (sub-pages) ----- */
.page-hero {
  min-height: 45vh; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(180deg, #0f0f23 0%, #1a1a3e 100%);
  position: relative; overflow: hidden; text-align: center;
  padding: calc(var(--header-height) + 40px) 20px 60px;
}
.page-hero::before {
  content:''; position:absolute; inset:0;
  background:
    radial-gradient(circle at 20% 80%, rgba(0,212,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(118,75,162,0.1) 0%, transparent 50%);
}
.page-hero > * { position: relative; z-index: 1; }
.page-hero .badge {
  display: inline-block; background: rgba(0,212,255,0.1); color: var(--accent-cyan);
  padding: 6px 18px; border-radius: 20px; font-size: 0.85rem;
  border: 1px solid var(--border-accent); margin-bottom: 20px;
}
.page-hero p { color: var(--text-secondary); font-size: 1.1rem; max-width: 600px; margin: 16px auto 0; }

/* ----- Buttons ----- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px 36px; border-radius: 50px; font-weight: 600; font-size: 1rem;
  transition: all 0.3s; cursor: pointer; border: none; white-space: nowrap;
}
.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 8px 30px rgba(0,212,255,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(0,212,255,0.4); }
.btn-outline {
  background: transparent; color: #fff;
  border: 1px solid rgba(255,255,255,0.2);
}
.btn-outline:hover { border-color: var(--accent-cyan); color: var(--accent-cyan); background: rgba(0,212,255,0.06); }
.btn-lg { padding: 18px 48px; font-size: 1.1rem; }
.btn-sm { padding: 10px 24px; font-size: 0.88rem; }

/* ----- Cards ----- */
.card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); padding: 36px 30px;
  transition: all 0.35s; position: relative; overflow: hidden;
}
.card:hover {
  transform: translateY(-6px);
  border-color: rgba(0,212,255,0.2);
  box-shadow: 0 16px 48px rgba(0,0,0,0.4);
}
.card-accent-top::before {
  content:''; position:absolute; top:0; left:0; right:0; height:3px;
  background: var(--gradient-h);
}
.card-cyan-glow:hover { box-shadow: 0 16px 48px rgba(0,212,255,0.12); }

/* ----- Grid ----- */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* ----- Stats Bar ----- */
.stats-bar {
  display: flex; justify-content: center; gap: 60px; flex-wrap: wrap;
  padding: 50px 24px;
}
.stat-item { text-align: center; }
.stat-num { font-size: 2.5rem; font-weight: 800; color: var(--accent-cyan); line-height: 1.2; }
.stat-label { font-size: 0.9rem; color: var(--text-muted); margin-top: 6px; }

/* ----- Pricing Card ----- */
.pricing-card {
  background: linear-gradient(145deg, #1a1a3e, #1f1f40);
  border: 1px solid var(--border-card); border-radius: var(--radius-xl);
  padding: 45px 32px; text-align: center; position: relative;
  transition: all 0.4s;
}
.pricing-card:hover { transform: translateY(-8px); border-color: rgba(0,212,255,0.3); box-shadow: var(--shadow-lg); }
.pricing-card.featured {
  border-color: rgba(0,212,255,0.3);
  box-shadow: 0 0 0 1px rgba(0,212,255,0.15), var(--shadow-cyan);
}
.pricing-card.featured::before {
  content:'推荐'; position:absolute; top:-14px; left:50%; transform:translateX(-50%);
  background: var(--gradient); color:#fff; padding:5px 22px; border-radius:20px;
  font-size:0.85rem; font-weight:600;
}
.pricing-card .pricing-name { font-size: 1.2rem; color: #fff; margin-bottom: 8px; }
.pricing-card .pricing-desc { color: var(--text-muted); font-size: 0.88rem; margin-bottom: 20px; }
.pricing-card .price { font-size: 2.8rem; font-weight: 800; color: var(--accent-cyan); margin: 16px 0; }
.pricing-card .price span { font-size: 0.95rem; color: var(--text-muted); font-weight: 400; }
.pricing-card ul { text-align: left; margin: 24px 0; }
.pricing-card li { padding: 10px 0; color: var(--text-secondary); font-size: 0.92rem; border-bottom: 1px solid var(--border-subtle); }
.pricing-card li::before { content:'✓ '; color: var(--accent-cyan); margin-right: 8px; font-weight: 700; }
.pricing-card .btn { width: 100%; margin-top: 8px; }
.pricing-card.featured .btn { background: var(--gradient); }

/* ----- FAQ Accordion ----- */
.faq-item { border-bottom: 1px solid var(--border-subtle); }
.faq-q {
  width: 100%; background: none; border: none; color: #fff;
  padding: 20px 0; font-size: 1.05rem; text-align: left; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
  transition: color 0.2s;
}
.faq-q:hover { color: var(--accent-cyan); }
.faq-q .arrow { transition: transform 0.3s; font-size: 0.8rem; color: var(--text-muted); }
.faq-q.open .arrow { transform: rotate(180deg); color: var(--accent-cyan); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; }
.faq-a > div { padding: 0 0 24px; color: var(--text-secondary); line-height: 1.9; }

/* ----- Timeline ----- */
.timeline { position: relative; padding-left: 40px; }
.timeline::before {
  content:''; position:absolute; left:8px; top:0; bottom:0;
  width:2px; background: linear-gradient(to bottom, var(--accent-cyan), var(--accent-purple));
  border-radius: 2px;
}
.timeline-item { position: relative; margin-bottom: 36px; }
.timeline-item::before {
  content:''; position:absolute; left:-36px; top:4px;
  width:14px; height:14px; border-radius:50%; background: var(--accent-cyan);
  border:3px solid var(--bg-primary); box-shadow: 0 0 12px rgba(0,212,255,0.4);
}
.timeline-item h4 { color: #fff; margin-bottom: 6px; }
.timeline-item p { color: var(--text-muted); font-size: 0.95rem; }

/* ----- Profile ----- */
.profile-grid { display: grid; grid-template-columns: 340px 1fr; gap: 50px; align-items: start; }
.profile-img img { width: 100%; border-radius: var(--radius-xl); border: 2px solid var(--border-accent); box-shadow: var(--shadow-lg); }
.profile-img .social { display: flex; gap: 12px; margin-top: 18px; justify-content: center; color: var(--text-muted); font-size: 0.88rem; }
.tag { display: inline-block; background: rgba(0,212,255,0.1); color: var(--accent-cyan); padding: 5px 15px; border-radius: 20px; font-size: 0.82rem; border: 1px solid var(--border-accent); margin-bottom: 16px; }

/* ----- Section Header ----- */
.section-header { text-align: center; margin-bottom: 50px; }
.section-header h2 { margin-bottom: 14px; }
.section-header p { color: var(--text-secondary); max-width: 600px; margin: 0 auto; font-size: 1.05rem; }

/* ----- Contact Cards ----- */
.contact-card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); padding: 36px 24px; text-align: center;
  transition: all 0.35s;
}
.contact-card:hover { border-color: var(--border-accent); transform: translateY(-4px); }
.contact-card .icon { font-size: 2.5rem; margin-bottom: 16px; }
.contact-card h3 { margin-bottom: 8px; }
.contact-card p, .contact-card a { color: var(--text-secondary); font-size: 0.95rem; }
.contact-card a:hover { color: var(--accent-cyan); }

/* ----- CTA Section ----- */
.cta-section {
  text-align: center; padding: 80px 24px;
  background: linear-gradient(135deg, rgba(0,212,255,0.04), rgba(118,75,162,0.06));
  border-top: 1px solid var(--border-subtle); border-bottom: 1px solid var(--border-subtle);
}
.cta-section h2 { margin-bottom: 12px; }
.cta-section p { color: var(--text-secondary); margin-bottom: 28px; font-size: 1.1rem; }

/* ----- Footer ----- */
.footer {
  background: #0a0a1a; border-top: 1px solid var(--border-subtle);
  padding: 48px 24px 24px;
}
.footer-inner {
  max-width: var(--container-max); margin: 0 auto;
  display: flex; justify-content: space-between; align-items: flex-start;
  gap: 40px; flex-wrap: wrap;
}
.footer-brand .logo-text { font-size: 1.1rem; font-weight: 700; }
.footer-brand p { color: var(--text-muted); font-size: 0.88rem; margin-top: 8px; }
.footer-links { display: flex; gap: 24px; flex-wrap: wrap; }
.footer-links a { color: var(--text-secondary); font-size: 0.9rem; transition: color 0.2s; }
.footer-links a:hover { color: var(--accent-cyan); }
.footer-links .col { display: flex; flex-direction: column; gap: 10px; min-width: 120px; }
.footer-links .col strong { color: #fff; font-size: 0.9rem; margin-bottom: 4px; }
.footer-bottom {
  max-width: var(--container-max); margin: 32px auto 0; padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
  text-align: center; color: var(--text-muted); font-size: 0.82rem;
}

/* ----- Chat Widget ----- */
.chat-widget {
  position: fixed; bottom: 80px; right: 24px; z-index: 9999;
  width: 380px; max-height: 520px;
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); overflow: hidden;
  display: none; flex-direction: column;
  box-shadow: 0 20px 60px rgba(0,0,0,0.6);
}
.chat-widget.open { display: flex; }
.chat-header {
  padding: 16px 20px; background: var(--gradient-h);
  display: flex; justify-content: space-between; align-items: center;
  font-weight: 700; font-size: 0.95rem;
}
.chat-header button { background: none; border: none; color: #fff; cursor: pointer; font-size: 1.2rem; }
.chat-messages { flex: 1; overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 12px; max-height: 340px; }
.chat-msg { padding: 12px 14px; border-radius: 12px; font-size: 0.9rem; line-height: 1.6; max-width: 85%; word-break: break-word; }
.chat-msg.bot { background: #252545; color: #fff; align-self: flex-start; border-bottom-left-radius: 4px; }
.chat-msg.user { background: var(--accent-cyan); color: var(--bg-primary); align-self: flex-end; border-bottom-right-radius: 4px; font-weight: 500; }
.chat-msg.typing { color: var(--text-muted); font-style: italic; }
.chat-input-wrap { padding: 12px 16px; border-top: 1px solid var(--border-subtle); display: flex; gap: 8px; }
.chat-input-wrap input {
  flex: 1; padding: 10px 14px; background: var(--bg-primary); border: 1px solid rgba(255,255,255,0.12);
  border-radius: 20px; color: #fff; outline: none; font-size: 0.9rem;
  transition: border-color 0.2s;
}
.chat-input-wrap input:focus { border-color: var(--accent-cyan); }
.chat-input-wrap button {
  width: 40px; height: 40px; border-radius: 50%; background: var(--gradient);
  border: none; color: #fff; cursor: pointer; font-size: 1.1rem;
  flex-shrink: 0; transition: opacity 0.2s;
}
.chat-input-wrap button:hover { opacity: 0.9; }

.chat-bubble {
  position: fixed; bottom: 24px; right: 24px; z-index: 9998;
  width: 56px; height: 56px; border-radius: 50%;
  background: var(--gradient); border: none; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; box-shadow: 0 8px 30px rgba(0,212,255,0.3);
  transition: transform 0.3s, box-shadow 0.3s;
}
.chat-bubble:hover { transform: scale(1.08); box-shadow: 0 14px 40px rgba(0,212,255,0.5); }
.chat-bubble.hidden { display: none; }

/* ----- Testimonials ----- */
.testimonial-card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); padding: 32px;
}
.testimonial-card .quote { color: var(--text-secondary); line-height: 1.9; font-size: 1rem; margin-bottom: 20px; }
.testimonial-card .quote::before { content:'"'; color: var(--accent-cyan); font-size: 2rem; margin-right: 4px; }
.testimonial-card .author { display: flex; align-items: center; gap: 12px; }
.testimonial-card .author-avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--gradient); display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 1.1rem; flex-shrink: 0;
}
.testimonial-card .author-info h4 { font-size: 0.95rem; color: #fff; }
.testimonial-card .author-info p { font-size: 0.82rem; color: var(--text-muted); }

/* ----- Process Steps ----- */
.process-track { display: flex; gap: 0; position: relative; }
.process-track::before {
  content:''; position:absolute; top:40px; left:10%; right:10%;
  height:2px; background: var(--gradient-h); opacity: 0.3;
}
.process-step { flex:1; text-align:center; position:relative; z-index:1; padding: 0 16px; }
.process-step .step-num {
  width: 56px; height: 56px; border-radius: 50%; margin: 0 auto 20px;
  background: var(--bg-secondary); border: 2px solid var(--accent-cyan);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; font-weight: 700; color: var(--accent-cyan);
  box-shadow: 0 0 20px rgba(0,212,255,0.15);
  transition: all 0.3s;
}
.process-step:hover .step-num { border-color: var(--accent-purple); box-shadow: 0 0 30px rgba(0,212,255,0.3); }
.process-step h4 { margin-bottom: 8px; }
.process-step p { color: var(--text-muted); font-size: 0.9rem; }

/* ----- Value Cards ----- */
.value-card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); padding: 40px 30px;
  transition: all 0.35s; position: relative; overflow: hidden;
}
.value-card:hover { transform: translateY(-6px); border-color: var(--border-accent); box-shadow: var(--shadow-lg); }
.value-card::before { content:''; position:absolute; top:0; left:0; right:0; height:3px; background: var(--gradient-h); }
.value-card .v-icon { font-size: 2.8rem; margin-bottom: 20px; }
.value-card h3 { margin-bottom: 12px; }
.value-card p { color: var(--text-secondary); line-height: 1.8; font-size: 0.95rem; }
.value-card ul { margin-top: 16px; }
.value-card li { padding: 8px 0; color: var(--text-secondary); font-size: 0.9rem; }
.value-card li::before { content:'→ '; color: var(--accent-cyan); }

/* ----- News Cards ----- */
.news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.news-card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); overflow: hidden; transition: all 0.35s;
}
.news-card:hover { transform: translateY(-4px); border-color: var(--border-accent); box-shadow: 0 16px 48px rgba(0,212,255,0.1); }
.news-card img { width: 100%; aspect-ratio: 16/10; object-fit: cover; }
.news-card .news-body { padding: 18px 20px; }
.news-card .news-body h3 { font-size: 0.95rem; line-height: 1.5; }
.news-card .news-body h3:hover { color: var(--accent-cyan); }
.news-card .news-meta { font-size: 0.8rem; color: var(--text-muted); margin-top: 8px; }

/* ── AI Q&A Section ─────────────────────────────── */
.ai-qa-section {
  padding: 80px 24px;
  background: linear-gradient(180deg, #0f0f23 0%, #13132a 50%, #0f0f23 100%);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  position: relative;
  overflow: hidden;
}
.ai-qa-section::before {
  content:''; position:absolute; inset:0;
  background:
    radial-gradient(circle at 50% 0%, rgba(0,212,255,0.06) 0%, transparent 60%),
    radial-gradient(circle at 80% 100%, rgba(118,75,162,0.05) 0%, transparent 50%);
  pointer-events: none;
}

.qa-hero-input {
  max-width: 720px; margin: 0 auto 32px;
  display: flex; gap: 12px;
}
.qa-hero-input input {
  flex: 1; padding: 16px 24px;
  background: var(--bg-card); border: 2px solid rgba(0,212,255,0.15);
  border-radius: 50px; color: #fff; font-size: 1.05rem;
  outline: none; transition: all 0.3s;
}
.qa-hero-input input:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 30px rgba(0,212,255,0.12);
}
.qa-hero-input input::placeholder { color: var(--text-muted); }
.qa-hero-input button {
  padding: 16px 32px; border-radius: 50px;
  background: var(--gradient); border: none; color: #fff;
  font-size: 1rem; font-weight: 600; cursor: pointer;
  white-space: nowrap; transition: all 0.3s;
  box-shadow: 0 8px 30px rgba(0,212,255,0.2);
}
.qa-hero-input button:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(0,212,255,0.35); }
.qa-hero-input button:disabled { opacity: 0.5; pointer-events: none; }

.qa-answer-box {
  max-width: 720px; margin: 0 auto 36px;
  background: var(--bg-card); border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg); padding: 24px 28px;
  display: none; animation: fadeUp 0.35s ease;
}
.qa-answer-box.open { display: block; }
.qa-answer-box .qa-answer-header {
  display: flex; align-items: center; gap: 10px; margin-bottom: 14px;
  font-size: 0.85rem; color: var(--accent-cyan); font-weight: 600;
}
.qa-answer-box .qa-answer-text {
  color: var(--text-secondary); line-height: 1.9; font-size: 0.98rem;
}
.qa-answer-box .qa-answer-text p { margin-bottom: 12px; }
.qa-answer-box .qa-answer-text p:last-child { margin-bottom: 0; }

.qa-hot-tags {
  max-width: 720px; margin: 0 auto 40px;
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
}
.qa-hot-tags .qa-hot-label {
  color: var(--text-muted); font-size: 0.85rem; white-space: nowrap;
}
.qa-hot-tags a {
  display: inline-block; padding: 7px 16px;
  background: rgba(0,212,255,0.06); border: 1px solid rgba(0,212,255,0.12);
  border-radius: 20px; color: var(--text-secondary); font-size: 0.85rem;
  transition: all 0.25s; cursor: pointer;
}
.qa-hot-tags a:hover {
  background: rgba(0,212,255,0.12); border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.qa-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; max-width: var(--container-max); margin: 0 auto 40px; }
.qa-card {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-lg); padding: 24px;
  transition: all 0.35s; cursor: pointer;
}
.qa-card:hover { transform: translateY(-4px); border-color: var(--border-accent); box-shadow: 0 12px 36px rgba(0,212,255,0.08); }
.qa-card .qa-card-q {
  font-weight: 600; color: #fff; font-size: 0.95rem;
  margin-bottom: 10px; line-height: 1.5;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.qa-card .qa-card-a {
  color: var(--text-muted); font-size: 0.85rem; line-height: 1.6;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.qa-card .qa-card-meta {
  display: flex; gap: 16px; margin-top: 14px;
  font-size: 0.78rem; color: var(--text-muted);
}

/* ── AI Q&A Full Page ─────────────────────────── */
.qa-stats-row { display: flex; gap: 48px; justify-content: center; margin-top: 20px; }
.qa-stats-row strong { font-size: 2rem; color: var(--accent-cyan); }
.qa-stats-row span { display: block; font-size: 0.8rem; color: var(--text-muted); }

.qa-categories {
  display: flex; gap: 8px; flex-wrap: wrap; justify-content: center;
  margin-bottom: 36px;
}
.qa-categories button {
  padding: 8px 20px; border-radius: 20px;
  background: var(--bg-card); border: 1px solid var(--border-card);
  color: var(--text-secondary); font-size: 0.88rem; cursor: pointer;
  transition: all 0.25s;
}
.qa-categories button:hover, .qa-categories button.active {
  background: rgba(0,212,255,0.1); border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.qa-list { max-width: 800px; margin: 0 auto; }
.qa-list-item {
  background: var(--bg-card); border: 1px solid var(--border-card);
  border-radius: var(--radius-md); margin-bottom: 12px;
  overflow: hidden; transition: all 0.3s;
}
.qa-list-item:hover { border-color: var(--border-accent); }
.qa-list-item .qa-li-q {
  padding: 20px 24px; display: flex; justify-content: space-between; align-items: center;
  cursor: pointer; font-weight: 600; font-size: 1rem; color: #fff;
  transition: color 0.2s; gap: 12px;
}
.qa-list-item .qa-li-q:hover { color: var(--accent-cyan); }
.qa-list-item .qa-li-q .qa-li-arrow {
  transition: transform 0.3s; font-size: 0.8rem; color: var(--text-muted);
  flex-shrink: 0;
}
.qa-list-item.open .qa-li-q .qa-li-arrow { transform: rotate(180deg); color: var(--accent-cyan); }
.qa-list-item .qa-li-a {
  max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
}
.qa-list-item .qa-li-a > div {
  padding: 0 24px 24px; color: var(--text-secondary); line-height: 1.9;
  font-size: 0.95rem;
}
.qa-list-item .qa-li-meta {
  display: flex; gap: 20px; padding: 0 24px 20px;
  font-size: 0.8rem; color: var(--text-muted);
}

.qa-pagination {
  display: flex; gap: 8px; justify-content: center; align-items: center;
  margin-top: 40px; flex-wrap: wrap;
}
.qa-pagination button, .qa-pagination span {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 40px; height: 40px; padding: 0 14px; border-radius: var(--radius-sm);
  font-size: 0.9rem; background: var(--bg-card); border: 1px solid var(--border-card);
  color: var(--text-secondary); transition: all 0.2s; cursor: pointer;
}
.qa-pagination button:hover { border-color: var(--accent-cyan); color: var(--accent-cyan); }
.qa-pagination button.active { background: var(--gradient); color: #fff; border-color: transparent; }
.qa-pagination button:disabled { opacity: 0.35; cursor: default; }

/* ── Utilities ─────────────────────────────────── */
.text-center { text-align: center; }
.mt-1 { margin-top: 8px; } .mt-2 { margin-top: 16px; } .mt-3 { margin-top: 24px; } .mt-4 { margin-top: 40px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; } .mb-3 { margin-bottom: 24px; } .mb-4 { margin-bottom: 40px; }
.hidden { display: none !important; }

/* ----- Responsive ----- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .qa-grid { grid-template-columns: repeat(2, 1fr); }
  .profile-grid { grid-template-columns: 1fr; max-width: 500px; margin: 0 auto; }
  .profile-img { max-width: 300px; margin: 0 auto; }
}

@media (max-width: 768px) {
  :root { --section-gap: 60px; }

  .nav-desktop { display: none; }
  .menu-toggle { display: block; }

  .grid-2, .grid-3, .grid-4, .news-grid, .qa-grid { grid-template-columns: 1fr; }
  .qa-hero-input { flex-direction: column; }
  .qa-hero-input button { padding: 14px 24px; }
  .qa-stats-row { gap: 24px; }
  .qa-stats-row strong { font-size: 1.5rem; }
  .stats-bar { gap: 30px; }
  .stat-num { font-size: 1.8rem; }

  .process-track { flex-direction: column; gap: 32px; }
  .process-track::before { display: none; }

  .chat-widget { width: calc(100vw - 40px); right: 20px; bottom: 70px; max-height: 50vh; }
  .chat-messages { max-height: 28vh; }

  .footer-inner { flex-direction: column; text-align: center; }
  .footer-links { justify-content: center; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .section { padding: 50px 16px; }
  .pricing-card { padding: 30px 20px; }
  .btn { padding: 12px 28px; font-size: 0.9rem; }
}

/* ----- Hero Particles (Homepage) ----- */
.hero-particles { position:absolute; inset:0; overflow:hidden; pointer-events:none; }
.hero-particle {
  position:absolute; border-radius:50%; background: var(--accent-cyan);
  animation: particleFloat linear infinite;
}
@keyframes particleFloat {
  0% { transform: translateY(105vh) rotate(0deg); opacity: 0; }
  8% { opacity: 0.8; }
  92% { opacity: 0.8; }
  100% { transform: translateY(-10vh) rotate(720deg); opacity: 0; }
}

/* ----- Animate on scroll fallback ----- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeUp 0.6s ease both; }

/* ----- Hero (Homepage specific) ----- */
.hero-home {
  min-height: 90vh; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #0f0f23 0%, #1a1a3e 50%, #0f0f23 100%);
  position: relative; overflow: hidden; text-align: center;
}
.hero-home::before {
  content:''; position:absolute; inset:0;
  background:
    radial-gradient(circle at 20% 80%, rgba(0,212,255,0.12) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(118,75,162,0.12) 0%, transparent 50%);
  animation: heroPulse 8s ease-in-out infinite;
}
@keyframes heroPulse {
  0%,100% { opacity: 1; }
  50% { opacity: 0.6; }
}
.hero-home .hero-content { position: relative; z-index: 1; max-width: 800px; padding: 20px; }
.hero-home h1 { margin-bottom: 20px; }
.hero-home .hero-sub { font-size: 1.2rem; color: var(--text-secondary); margin-bottom: 32px; animation: fadeUp 0.8s ease 0.2s both; }
.hero-home .hero-quote { font-size: 1rem; color: var(--accent-cyan); margin-top: 36px; font-style: italic; animation: fadeUp 0.8s ease 0.5s both; }

/* ----- Breadcrumb ----- */
.breadcrumb { padding: calc(var(--header-height) + 16px) 24px 0; max-width: var(--container-max); margin: 0 auto; }
.breadcrumb a { color: var(--text-muted); font-size: 0.85rem; }
.breadcrumb a:hover { color: var(--accent-cyan); }
.breadcrumb span { color: var(--text-muted); font-size: 0.85rem; margin: 0 6px; }

/* ----- Article Content ----- */
.article { max-width: 800px; margin: 0 auto; padding: 0 24px; }
.article h2 { font-size: 1.6rem; margin: 36px 0 16px; }
.article p { color: var(--text-secondary); margin-bottom: 18px; line-height: 1.9; font-size: 1.02rem; }
.article img { border-radius: var(--radius-md); margin: 24px 0; }
.article blockquote { border-left: 3px solid var(--accent-cyan); padding-left: 20px; color: var(--text-muted); margin: 24px 0; font-style: italic; }