/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: var(--gradient-hero);
  padding-top: var(--header-height);
}

.hero::before {
  content: '';
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(59,130,246,0.12) 0%, rgba(139,92,246,0.06) 40%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero h1 {
  margin-bottom: var(--space-6);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Model Strip ===== */
.model-strip {
  background: var(--color-bg-secondary);
  border-top: 1px solid rgba(255,255,255,0.04);
  border-bottom: 1px solid rgba(255,255,255,0.04);
  padding: var(--space-10) 0;
}

.model-strip-label {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-6);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.model-strip-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
}

.model-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg-tertiary);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 100px;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.model-chip:hover {
  border-color: rgba(59,130,246,0.3);
  color: var(--color-text-primary);
}

.model-chip .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.dot-openai { background: var(--color-green); }
.dot-zhipu { background: var(--color-accent); }
.dot-alibaba { background: var(--color-amber); }

/* ===== Features ===== */
.features { background: var(--color-bg-primary); }

.feature-card .card-icon {
  width: 56px;
  height: 56px;
  font-size: 24px;
}

/* ===== Chat Demo ===== */
.chat-demo-section {
  background: var(--color-bg-secondary);
}

.chat-container {
  max-width: 800px;
  margin: 0 auto;
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--color-bg-primary);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.chat-header-left {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.chat-status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-green);
}

.chat-status::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.chat-model-select {
  padding: var(--space-1) var(--space-3);
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius);
  color: var(--color-text-primary);
  font-size: var(--text-xs);
  font-family: var(--font-sans);
  cursor: pointer;
}

.chat-messages {
  height: 400px;
  overflow-y: auto;
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.chat-message {
  display: flex;
  gap: var(--space-3);
  max-width: 85%;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } }

.chat-message.user { align-self: flex-end; flex-direction: row-reverse; }

.chat-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 600;
}

.chat-message.assistant .chat-avatar {
  background: var(--gradient-accent);
  color: #fff;
}

.chat-message.user .chat-avatar {
  background: rgba(255,255,255,0.1);
  color: var(--color-text-secondary);
}

.chat-bubble {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  line-height: 1.7;
}

.chat-message.assistant .chat-bubble {
  background: var(--color-bg-tertiary);
  border: 1px solid rgba(255,255,255,0.06);
  color: var(--color-text-secondary);
}

.chat-message.user .chat-bubble {
  background: var(--color-accent);
  color: #fff;
}

.chat-bubble pre {
  margin: var(--space-2) 0;
  font-size: var(--text-xs);
}

.chat-bubble code { font-size: inherit; }

.typing-indicator span {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-text-tertiary);
  animation: typingDot 1.4s infinite;
  margin: 0 1px;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingDot {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
  30% { transform: translateY(-4px); opacity: 1; }
}

.chat-examples {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid rgba(255,255,255,0.04);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chat-example-btn {
  padding: var(--space-1) var(--space-3);
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 100px;
  color: var(--color-text-tertiary);
  font-size: var(--text-xs);
  cursor: pointer;
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

.chat-example-btn:hover {
  background: rgba(59,130,246,0.1);
  border-color: rgba(59,130,246,0.3);
  color: var(--color-accent);
}

.chat-input-area {
  display: flex;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-tertiary);
  border-top: 1px solid rgba(255,255,255,0.06);
}

.chat-input {
  flex: 1;
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-primary);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius);
  color: var(--color-text-primary);
  font-size: var(--text-sm);
  font-family: var(--font-sans);
  outline: none;
}

.chat-input:focus { border-color: var(--color-accent); }

.chat-send-btn {
  padding: var(--space-2) var(--space-4);
  background: var(--gradient-accent);
  border: none;
  border-radius: var(--radius);
  color: #fff;
  font-size: var(--text-sm);
  cursor: pointer;
  font-family: var(--font-sans);
  transition: opacity var(--transition-fast);
  white-space: nowrap;
}

.chat-send-btn:hover { opacity: 0.9; }
.chat-send-btn:disabled { opacity: 0.4; cursor: not-allowed; }

.chat-footer {
  text-align: center;
  padding: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

/* ===== Quick Start ===== */
.quickstart { background: var(--color-bg-primary); }

.quickstart-wrap {
  max-width: 700px;
  margin: 0 auto;
}

/* ===== CTA Banner ===== */
.cta-banner {
  background: var(--gradient-hero);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(59,130,246,0.15), transparent 60%);
}

.cta-banner .container { position: relative; z-index: 1; }
.cta-banner h2 { margin-bottom: var(--space-4); }
.cta-banner p { margin-bottom: var(--space-6); color: var(--color-text-secondary); }

@media (max-width: 640px) {
  .chat-messages { height: 300px; }
  .chat-message { max-width: 95%; }
  .chat-examples { display: none; }
}