* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f0f2f5;
    min-height: 100vh;
}

.container {
    max-width: 500px;
    margin: 60px auto;
    padding: 20px;
}
h1 { text-align: center; margin-bottom: 20px; color: #333; }
.card {
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}
.card h2 { font-size: 18px; margin-bottom: 15px; color: #444; }
input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    margin-bottom: 10px;
    font-size: 14px;
}
.btn-primary {
    background: #0078ff;
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}
.btn-primary:hover { background: #0062d6; }
.link-box {
    margin-top: 15px;
    padding: 12px;
    background: #e8f3ff;
    border-radius: 6px;
}
.link-box input {
    background: #fff;
    font-family: monospace;
    font-size: 12px;
}
.error { color: #d33; margin-bottom: 10px; }

/* Chat UI */
.chat-wrapper {
    max-width: 700px;
    margin: 20px auto;
    height: calc(100vh - 40px);
    display: flex;
    flex-direction: column;
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 20px rgba(0,0,0,0.1);
}
.chat-header {
    background: #0078ff;
    color: #fff;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.chat-header small { opacity: 0.8; }
.messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #f9fafb;
}
.msg {
    margin-bottom: 12px;
    padding: 8px 12px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.msg-user {
    font-weight: 600;
    color: #0078ff;
    font-size: 13px;
    margin-right: 8px;
}
.msg-time { font-size: 11px; color: #999; }
.msg-text { margin-top: 4px; font-size: 14px; word-wrap: break-word; white-space: pre-wrap; }
.chat-input {
    display: flex;
    gap: 8px;
    padding: 12px;
    background: #fff;
    border-top: 1px solid #eee;
}
.chat-input input { margin-bottom: 0; }
#username { flex: 0 0 120px; }
#messageInput { flex: 1; }
#sendBtn {
    background: #0078ff;
    color: #fff;
    border: none;
    padding: 0 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}
#sendBtn:hover { background: #0062d6; }