/* =============================================
   AI 概念演示 - 主样式表
   暗色科技风格
   ============================================= */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg-dark: #0a0e1a;
  --bg-card: rgba(15, 20, 40, 0.85);
  --bg-card-hover: rgba(25, 35, 65, 0.9);
  --neon-blue: #00d4ff;
  --neon-purple: #a855f7;
  --neon-pink: #f472b6;
  --neon-green: #22d3ee;
  --neon-orange: #fb923c;
  --text-main: #e2e8f0;
  --text-dim: #94a3b8;
  --text-bright: #ffffff;
  --glow-blue: 0 0 20px rgba(0, 212, 255, 0.3);
  --glow-purple: 0 0 20px rgba(168, 85, 247, 0.3);
  --glow-pink: 0 0 20px rgba(244, 114, 182, 0.3);
  --gradient-main: linear-gradient(135deg, var(--neon-blue), var(--neon-purple));
  --gradient-warm: linear-gradient(135deg, var(--neon-pink), var(--neon-orange));
  --radius: 16px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  background: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--neon-purple); border-radius: 3px; }

/* ---------- Canvas Background ---------- */
#particle-canvas {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ---------- Navigation ---------- */
.nav-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  justify-content: center;
  gap: 8px;
  padding: 16px 20px;
  background: rgba(10, 14, 26, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.05);
  transition: transform 0.4s;
}
.nav-bar.hidden { transform: translateY(-100%); }
.nav-btn {
  padding: 8px 20px;
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 30px;
  background: transparent;
  color: var(--text-dim);
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}
.nav-btn:hover, .nav-btn.active {
  color: var(--neon-blue);
  border-color: var(--neon-blue);
  box-shadow: var(--glow-blue);
  background: rgba(0, 212, 255, 0.05);
}

/* ---------- Sections Common ---------- */
.section {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  padding: 120px 5% 80px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.section-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  border-radius: 30px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 16px;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s;
}
.section-badge.visible { opacity: 1; transform: translateY(0); }
.badge-blue { border: 1px solid var(--neon-blue); color: var(--neon-blue); background: rgba(0,212,255,0.08); }
.badge-purple { border: 1px solid var(--neon-purple); color: var(--neon-purple); background: rgba(168,85,247,0.08); }
.badge-pink { border: 1px solid var(--neon-pink); color: var(--neon-pink); background: rgba(244,114,182,0.08); }
.badge-green { border: 1px solid var(--neon-green); color: var(--neon-green); background: rgba(34,211,238,0.08); }

.section-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  text-align: center;
  margin-bottom: 12px;
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.7s 0.1s;
}
.section-title.visible { opacity: 1; transform: translateY(0); }

.section-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-dim);
  text-align: center;
  max-width: 680px;
  margin-bottom: 48px;
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.7s 0.2s;
}
.section-subtitle.visible { opacity: 1; transform: translateY(0); }

.gradient-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.gradient-warm {
  background: var(--gradient-warm);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Hero Section ---------- */
#hero {
  min-height: 100vh;
  justify-content: center;
  text-align: center;
}
.hero-icon {
  font-size: 4rem;
  margin-bottom: 20px;
  animation: float 3s ease-in-out infinite;
}
.hero-title {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
}
.hero-desc {
  font-size: clamp(1rem, 2.5vw, 1.3rem);
  color: var(--text-dim);
  max-width: 600px;
  margin: 0 auto 40px;
}
.hero-tags {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 48px;
}
.hero-tag {
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: default;
  display: flex;
  align-items: center;
  gap: 8px;
}
.tag-blue { background: rgba(0,212,255,0.12); color: var(--neon-blue); border: 1px solid rgba(0,212,255,0.3); }
.tag-purple { background: rgba(168,85,247,0.12); color: var(--neon-purple); border: 1px solid rgba(168,85,247,0.3); }
.tag-pink { background: rgba(244,114,182,0.12); color: var(--neon-pink); border: 1px solid rgba(244,114,182,0.3); }

.scroll-hint {
  position: absolute;
  bottom: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 0.85rem;
  animation: bounce 2s ease-in-out infinite;
}
.scroll-arrow {
  width: 24px; height: 40px;
  border: 2px solid var(--text-dim);
  border-radius: 12px;
  position: relative;
}
.scroll-arrow::after {
  content: '';
  position: absolute;
  top: 8px; left: 50%;
  transform: translateX(-50%);
  width: 4px; height: 8px;
  background: var(--neon-blue);
  border-radius: 2px;
  animation: scroll-dot 2s ease-in-out infinite;
}

/* ---------- Cards ---------- */
.card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 32px;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}
.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255,255,255,0.12);
  transform: translateY(-2px);
}

/* ---------- Demo Containers ---------- */
.demo-container {
  width: 100%;
  max-width: 1100px;
  opacity: 0;
  transform: translateY(40px);
  transition: all 0.8s 0.3s;
}
.demo-container.visible { opacity: 1; transform: translateY(0); }

/* ---------- AI Model Section ---------- */
.model-demo {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

/* Analogy Card */
.analogy-box {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.analogy-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  transition: var(--transition);
}
.analogy-card:hover { border-color: rgba(0,212,255,0.3); }
.analogy-icon { font-size: 2.5rem; margin-bottom: 12px; }
.analogy-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; color: var(--text-bright); }
.analogy-desc { font-size: 0.9rem; color: var(--text-dim); }

/* Training Animation */
.training-demo {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.training-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  padding: 30px 0;
}
.flow-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  min-width: 120px;
}
.flow-icon-box {
  width: 80px; height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  transition: all 0.5s;
  position: relative;
}
.flow-icon-box.active {
  transform: scale(1.15);
}
.flow-icon-box::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid transparent;
  transition: all 0.5s;
}
.flow-icon-box.active::after {
  border-color: currentColor;
  animation: pulse-ring 1.5s ease-out infinite;
}
.flow-step-label { font-size: 0.85rem; color: var(--text-dim); font-weight: 600; }
.flow-arrow {
  font-size: 1.5rem;
  color: var(--text-dim);
  opacity: 0.3;
  transition: all 0.5s;
}
.flow-arrow.active { opacity: 1; color: var(--neon-blue); }
.step-blue .flow-icon-box { background: rgba(0,212,255,0.12); color: var(--neon-blue); }
.step-purple .flow-icon-box { background: rgba(168,85,247,0.12); color: var(--neon-purple); }
.step-green .flow-icon-box { background: rgba(34,211,238,0.12); color: var(--neon-green); }

.training-progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255,255,255,0.06);
  border-radius: 3px;
  overflow: hidden;
}
.training-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--gradient-main);
  border-radius: 3px;
  transition: width 0.3s;
}
.training-status {
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-dim);
  min-height: 24px;
}

/* Interactive Chat */
.chat-demo {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  overflow: hidden;
}
.chat-header {
  padding: 16px 24px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  gap: 12px;
}
.chat-header-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--neon-green);
  box-shadow: 0 0 8px rgba(34,211,238,0.5);
}
.chat-header-title { font-weight: 600; font-size: 0.9rem; }
.chat-body {
  padding: 24px;
  min-height: 220px;
  max-height: 350px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.chat-msg {
  max-width: 85%;
  padding: 14px 18px;
  border-radius: 16px;
  font-size: 0.95rem;
  line-height: 1.6;
  animation: msg-in 0.4s ease;
}
.chat-msg.user {
  align-self: flex-end;
  background: rgba(0,212,255,0.12);
  border: 1px solid rgba(0,212,255,0.2);
  border-bottom-right-radius: 4px;
  color: var(--neon-blue);
}
.chat-msg.ai {
  align-self: flex-start;
  background: rgba(168,85,247,0.1);
  border: 1px solid rgba(168,85,247,0.15);
  border-bottom-left-radius: 4px;
}
.chat-msg.ai .thinking {
  display: inline-block;
  color: var(--text-dim);
}
.chat-input-row {
  padding: 16px 24px;
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex;
  gap: 12px;
}
.chat-input {
  flex: 1;
  padding: 12px 18px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.03);
  color: var(--text-main);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: var(--transition);
}
.chat-input:focus { border-color: var(--neon-blue); }
.chat-input::placeholder { color: var(--text-dim); }
.chat-send-btn {
  padding: 12px 24px;
  border: none;
  border-radius: 12px;
  background: var(--gradient-main);
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  font-size: 0.9rem;
}
.chat-send-btn:hover { transform: scale(1.03); box-shadow: var(--glow-blue); }
.chat-send-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.quick-questions {
  padding: 0 24px 16px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.quick-q-btn {
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid rgba(255,255,255,0.1);
  background: transparent;
  color: var(--text-dim);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}
.quick-q-btn:hover {
  border-color: var(--neon-blue);
  color: var(--neon-blue);
  background: rgba(0,212,255,0.05);
}

/* ---------- Agent Section ---------- */
.agent-demo {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.agent-analogy {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}
.agent-vs-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
}
.agent-vs-card .icon { font-size: 2.2rem; margin-bottom: 10px; }
.agent-vs-card .label { font-size: 0.85rem; color: var(--text-dim); margin-bottom: 6px; }
.agent-vs-card .title { font-weight: 700; font-size: 1.05rem; color: var(--text-bright); margin-bottom: 8px; }
.agent-vs-card .desc { font-size: 0.85rem; color: var(--text-dim); }
.vs-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 900;
  color: var(--neon-purple);
}

/* Task Demo */
.task-demo-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  overflow: hidden;
}
.task-header {
  padding: 20px 28px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.task-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}
.task-header-icon {
  width: 40px; height: 40px;
  border-radius: 10px;
  background: rgba(168,85,247,0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}
.task-header-title { font-weight: 700; font-size: 1rem; }
.task-header-subtitle { font-size: 0.8rem; color: var(--text-dim); }
.task-start-btn {
  padding: 10px 24px;
  border: none;
  border-radius: 10px;
  background: rgba(168,85,247,0.15);
  color: var(--neon-purple);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  border: 1px solid rgba(168,85,247,0.3);
}
.task-start-btn:hover { background: rgba(168,85,247,0.25); box-shadow: var(--glow-purple); }
.task-start-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.task-body { padding: 28px; }

.task-input-area {
  margin-bottom: 24px;
}
.task-input-label {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.task-input {
  width: 100%;
  padding: 14px 18px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.03);
  color: var(--text-main);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: var(--transition);
  resize: none;
}
.task-input:focus { border-color: var(--neon-purple); }

.agent-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.agent-step {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  opacity: 0.3;
  transition: all 0.5s;
}
.agent-step.active { opacity: 1; }
.agent-step.done { opacity: 0.7; }
.step-line {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 36px;
  flex-shrink: 0;
}
.step-dot {
  width: 36px; height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  background: rgba(255,255,255,0.05);
  border: 2px solid rgba(255,255,255,0.1);
  transition: all 0.5s;
  flex-shrink: 0;
}
.agent-step.active .step-dot {
  background: rgba(168,85,247,0.2);
  border-color: var(--neon-purple);
  color: var(--neon-purple);
  box-shadow: var(--glow-purple);
}
.agent-step.done .step-dot {
  background: rgba(34,211,238,0.15);
  border-color: var(--neon-green);
  color: var(--neon-green);
}
.step-connector {
  width: 2px;
  flex: 1;
  min-height: 20px;
  background: rgba(255,255,255,0.06);
  transition: background 0.5s;
}
.agent-step.done .step-connector { background: rgba(34,211,238,0.3); }
.step-content { flex: 1; padding-bottom: 8px; }
.step-title { font-weight: 700; font-size: 0.95rem; margin-bottom: 4px; }
.step-desc { font-size: 0.85rem; color: var(--text-dim); }
.step-result {
  margin-top: 10px;
  padding: 12px 16px;
  background: rgba(168,85,247,0.06);
  border-radius: 10px;
  border: 1px solid rgba(168,85,247,0.1);
  font-size: 0.85rem;
  color: var(--text-main);
  line-height: 1.6;
  display: none;
}
.agent-step.done .step-result { display: block; animation: msg-in 0.4s ease; }

/* ---------- Skill Section ---------- */
.skill-demo {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.skill-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}
.skill-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.skill-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-main);
  opacity: 0;
  transition: opacity 0.3s;
}
.skill-card:hover::before { opacity: 0.05; }
.skill-card.selected {
  border-color: var(--neon-pink);
  box-shadow: var(--glow-pink);
}
.skill-card.selected::before { opacity: 0.08; }
.skill-icon {
  font-size: 2rem;
  margin-bottom: 10px;
  position: relative;
  z-index: 1;
}
.skill-name {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 6px;
  position: relative;
  z-index: 1;
  color: var(--text-bright);
}
.skill-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
  position: relative;
  z-index: 1;
}
.skill-check {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--neon-pink);
  color: white;
  font-size: 0.7rem;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 2;
}
.skill-card.selected .skill-check { display: flex; }

/* Skill Workshop */
.skill-workshop {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  overflow: hidden;
}
.workshop-header {
  padding: 20px 28px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.workshop-title-row {
  display: flex;
  align-items: center;
  gap: 10px;
}
.workshop-title { font-weight: 700; font-size: 1rem; }
.workshop-run-btn {
  padding: 10px 24px;
  border: none;
  border-radius: 10px;
  background: rgba(244,114,182,0.15);
  color: var(--neon-pink);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  border: 1px solid rgba(244,114,182,0.3);
}
.workshop-run-btn:hover { background: rgba(244,114,182,0.25); box-shadow: var(--glow-pink); }
.workshop-run-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.workshop-body {
  padding: 28px;
}
.selected-skills {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 24px;
  min-height: 50px;
  padding: 16px;
  border: 2px dashed rgba(255,255,255,0.08);
  border-radius: 12px;
  align-items: center;
}
.selected-skill-tag {
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
  animation: msg-in 0.3s ease;
}
.tag-style-1 { background: rgba(0,212,255,0.12); color: var(--neon-blue); border: 1px solid rgba(0,212,255,0.2); }
.tag-style-2 { background: rgba(168,85,247,0.12); color: var(--neon-purple); border: 1px solid rgba(168,85,247,0.2); }
.tag-style-3 { background: rgba(244,114,182,0.12); color: var(--neon-pink); border: 1px solid rgba(244,114,182,0.2); }
.tag-style-4 { background: rgba(34,211,238,0.12); color: var(--neon-green); border: 1px solid rgba(34,211,238,0.2); }
.tag-style-5 { background: rgba(251,146,60,0.12); color: var(--neon-orange); border: 1px solid rgba(251,146,60,0.2); }

.empty-skills-hint {
  color: var(--text-dim);
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-output {
  padding: 20px;
  background: rgba(255,255,255,0.02);
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.05);
  min-height: 120px;
}
.skill-output-title {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.skill-output-content {
  font-size: 0.9rem;
  line-height: 1.8;
}
.skill-output-content .highlight {
  color: var(--neon-pink);
  font-weight: 600;
}

/* ---------- Final Section ---------- */
.final-demo {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

/* Relationship Diagram */
.relationship-diagram {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  padding: 40px;
  position: relative;
  min-height: 320px;
}
.rel-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
}
.rel-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 30px;
  flex-wrap: wrap;
}
.rel-node {
  width: 140px; height: 140px;
  border-radius: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all 0.5s;
  cursor: pointer;
  position: relative;
}
.rel-node::after {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 2px solid transparent;
  transition: all 0.5s;
}
.rel-node:hover::after { border-color: currentColor; }
.rel-node .icon { font-size: 2rem; }
.rel-node .name { font-weight: 700; font-size: 0.9rem; }
.rel-node .sub { font-size: 0.7rem; opacity: 0.6; }
.rel-node-blue { background: rgba(0,212,255,0.1); border: 2px solid rgba(0,212,255,0.3); color: var(--neon-blue); }
.rel-node-purple { background: rgba(168,85,247,0.1); border: 2px solid rgba(168,85,247,0.3); color: var(--neon-purple); }
.rel-node-pink { background: rgba(244,114,182,0.1); border: 2px solid rgba(244,114,182,0.3); color: var(--neon-pink); }

.rel-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: var(--text-dim);
  font-size: 0.75rem;
}
.rel-arrow i { font-size: 1.2rem; }

.rel-desc {
  text-align: center;
  padding: 20px;
  background: rgba(255,255,255,0.02);
  border-radius: 12px;
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.8;
  transition: all 0.4s;
  min-height: 60px;
}
.rel-desc .hl-blue { color: var(--neon-blue); font-weight: 600; }
.rel-desc .hl-purple { color: var(--neon-purple); font-weight: 600; }
.rel-desc .hl-pink { color: var(--neon-pink); font-weight: 600; }

/* Full Case Demo */
.case-demo {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius);
  overflow: hidden;
}
.case-header {
  padding: 24px 28px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  background: linear-gradient(135deg, rgba(0,212,255,0.05), rgba(168,85,247,0.05), rgba(244,114,182,0.05));
}
.case-header-left {
  display: flex;
  align-items: center;
  gap: 14px;
}
.case-avatar {
  width: 48px; height: 48px;
  border-radius: 50%;
  background: var(--gradient-warm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
}
.case-title { font-weight: 700; font-size: 1.1rem; color: var(--text-bright); }
.case-subtitle { font-size: 0.8rem; color: var(--text-dim); }
.case-play-btn {
  padding: 12px 28px;
  border: none;
  border-radius: 12px;
  background: var(--gradient-main);
  color: white;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.case-play-btn:hover { transform: scale(1.03); }
.case-play-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.case-body { padding: 28px; }
.case-timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.case-step {
  display: flex;
  gap: 16px;
  padding: 12px 0;
  opacity: 0.2;
  transition: all 0.6s;
}
.case-step.active { opacity: 1; }
.case-step.done { opacity: 0.8; }
.case-step-line {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 40px;
  flex-shrink: 0;
}
.case-step-icon {
  width: 40px; height: 40px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  flex-shrink: 0;
  transition: all 0.5s;
}
.case-step.active .case-step-icon {
  border-color: var(--neon-blue);
  box-shadow: var(--glow-blue);
}
.case-step.done .case-step-icon {
  background: rgba(34,211,238,0.1);
  border-color: var(--neon-green);
}
.case-step-connector {
  width: 2px;
  flex: 1;
  min-height: 10px;
  background: rgba(255,255,255,0.04);
}
.case-step.done .case-step-connector { background: rgba(34,211,238,0.2); }
.case-step-content { flex: 1; padding-bottom: 4px; }
.case-step-label {
  font-size: 0.7rem;
  padding: 2px 10px;
  border-radius: 4px;
  display: inline-block;
  margin-bottom: 6px;
  font-weight: 600;
}
.label-model { background: rgba(0,212,255,0.1); color: var(--neon-blue); }
.label-agent { background: rgba(168,85,247,0.1); color: var(--neon-purple); }
.label-skill { background: rgba(244,114,182,0.1); color: var(--neon-pink); }
.case-step-title { font-weight: 700; font-size: 0.95rem; margin-bottom: 4px; }
.case-step-desc { font-size: 0.82rem; color: var(--text-dim); line-height: 1.6; }
.case-step-output {
  margin-top: 10px;
  padding: 12px 16px;
  background: rgba(255,255,255,0.02);
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.05);
  font-size: 0.82rem;
  line-height: 1.7;
  display: none;
}
.case-step.done .case-step-output { display: block; animation: msg-in 0.5s ease; }

/* Footer */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 40px 20px;
  color: var(--text-dim);
  font-size: 0.8rem;
  border-top: 1px solid rgba(255,255,255,0.04);
}

/* ---------- Animations ---------- */
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}
@keyframes scroll-dot {
  0% { top: 8px; opacity: 1; }
  100% { top: 22px; opacity: 0; }
}
@keyframes pulse-ring {
  0% { transform: scale(1); opacity: 1; }
  100% { transform: scale(1.3); opacity: 0; }
}
@keyframes msg-in {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes typing-blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}
.typing-cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--neon-purple);
  margin-left: 2px;
  animation: typing-blink 0.8s step-end infinite;
  vertical-align: text-bottom;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .section { padding: 100px 4% 60px; }
  .nav-bar { gap: 4px; padding: 12px 10px; }
  .nav-btn { padding: 6px 12px; font-size: 0.75rem; }
  .training-flow { gap: 6px; }
  .flow-icon-box { width: 60px; height: 60px; font-size: 1.5rem; }
  .rel-node { width: 100px; height: 100px; }
  .rel-node .icon { font-size: 1.5rem; }
  .rel-node .name { font-size: 0.75rem; }
  .rel-row { gap: 15px; }
  .hero-tags { gap: 10px; }
  .hero-tag { padding: 10px 20px; font-size: 0.85rem; }
  .agent-analogy { grid-template-columns: 1fr 1fr; }
  .vs-divider { display: none; }
  .skill-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
}