*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  background: #050816;
  color: #e5e7eb;
}

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px 40px;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
  margin-bottom: 16px;
}

.header h1 {
  margin: 0 0 8px;
  font-size: 26px;
  color: #f9fafb;
}

.subtitle {
  margin: 0;
  font-size: 14px;
  color: #9ca3af;
}

.price-box {
  text-align: right;
}

.price {
  font-size: 28px;
  font-weight: 700;
  color: #fbbf24;
}

.price-note {
  font-size: 12px;
  color: #9ca3af;
}

.main {
  display: grid;
  grid-template-columns: minmax(0, 2.1fr) minmax(0, 1.2fr);
  gap: 20px;
  align-items: flex-start;
}

.chat-section,
.info-section {
  background: radial-gradient(circle at top left, #1f2937, #020617 60%);
  border-radius: 14px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.85);
}

.chat-section {
  display: flex;
  flex-direction: column;
  height: 70vh;
  min-height: 420px;
}

.chat-window {
  flex: 1;
  padding: 14px 16px;
  overflow-y: auto;
}

.chat-input {
  display: flex;
  gap: 8px;
  padding: 10px;
  border-top: 1px solid rgba(148, 163, 184, 0.4);
  background: rgba(15, 23, 42, 0.9);
  border-radius: 0 0 14px 14px;
}

.chat-input textarea {
  flex: 1;
  resize: none;
  min-height: 48px;
  max-height: 96px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid rgba(148, 163, 184, 0.7);
  background: rgba(15, 23, 42, 0.95);
  color: #e5e7eb;
  font-size: 14px;
}

.chat-input textarea:focus {
  outline: none;
  border-color: #7dd3fc;
  box-shadow: 0 0 0 1px rgba(125, 211, 252, 0.4);
}

.chat-input button {
  padding: 0 18px;
  border-radius: 10px;
  border: none;
  background: linear-gradient(135deg, #0ea5e9, #6366f1);
  color: #f9fafb;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.08s ease, box-shadow 0.08s ease, opacity 0.1s ease;
}

.chat-input button:disabled {
  opacity: 0.5;
  cursor: default;
}

.chat-input button:not(:disabled):hover {
  box-shadow: 0 8px 20px rgba(59, 130, 246, 0.6);
  transform: translateY(-1px);
}

.message-row {
  display: flex;
  margin-bottom: 10px;
}

.message-row.user {
  justify-content: flex-end;
}

.message-row.assistant {
  justify-content: flex-start;
}

.message-bubble {
  max-width: 80%;
  padding: 8px 10px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
}

.message-row.user .message-bubble {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: #ecfdf5;
  border-bottom-right-radius: 4px;
}

.message-row.assistant .message-bubble {
  background: rgba(15, 23, 42, 0.92);
  border: 1px solid rgba(148, 163, 184, 0.6);
  border-bottom-left-radius: 4px;
}

.info-section {
  padding: 16px 16px 18px;
}

.info-section h2 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 18px;
  color: #e5e7eb;
}

.info-section ul {
  padding-left: 20px;
  margin: 4px 0 12px;
  font-size: 14px;
  color: #d1d5db;
}

.tip-box {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 10px;
  background: rgba(8, 47, 73, 0.9);
  border: 1px solid rgba(56, 189, 248, 0.6);
  font-size: 13px;
  color: #e0f2fe;
}

@media (max-width: 900px) {
  .main {
    grid-template-columns: minmax(0, 1fr);
  }

  .chat-section {
    height: 60vh;
  }

  .price-box {
    text-align: left;
  }
}