:root {
  --bg: #eef2f6;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #d1d9e6;
  --primary: #0d5bd7;
  --primary-hover: #0a4aaf;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top right, #dce8ff 0, transparent 40%),
    linear-gradient(180deg, #f6f9ff 0%, var(--bg) 100%);
}

.container {
  max-width: 900px;
  margin: 24px auto;
  padding: 0 16px 24px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 8px 22px rgba(31, 41, 55, 0.08);
}

h1 {
  margin: 0 0 10px;
  font-size: 2rem;
  line-height: 1.15;
}

.meta {
  color: var(--muted);
  margin: 4px 0 10px;
  font-size: 0.94rem;
}

.form {
  display: grid;
  gap: 10px;
}

label {
  display: grid;
  gap: 6px;
  font-weight: 600;
  font-size: 0.95rem;
}

input,
button {
  font: inherit;
}

input {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  background: #fff;
}

button {
  border: none;
  border-radius: 8px;
  padding: 10px 14px;
  background: var(--primary);
  color: #fff;
  cursor: pointer;
  font-weight: 700;
}

button:hover {
  background: var(--primary-hover);
}

.chat-log {
  margin-top: 10px;
  display: grid;
  gap: 8px;
  max-height: 560px;
  overflow-y: auto;
  padding-right: 4px;
}

.message {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
  background: #fff;
}

.message.user {
  background: #e8f1ff;
}

.message.assistant {
  background: #f2fffb;
  border-color: #bde5dc;
}

.message-body {
  white-space: pre-line;
  line-height: 1.35;
}

.message-body a {
  color: #0a4aaf;
  font-weight: 600;
}

.chat-form {
  position: sticky;
  bottom: 0;
  background: var(--panel);
  padding-top: 8px;
  margin-top: 10px;
}