* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: #f5f5f5;
    height: 100vh;
    display: flex;
    color: #333;
}
.container {
    display: flex;
    width: 100%;
    height: 100%;
}
.sidebar {
    width: 260px;
    background: #fff;
    border-right: 1px solid #e0e0e0;
    display: flex;
    flex-direction: column;
    padding: 16px;
}
.sidebar h3 {
    font-size: 14px;
    color: #555;
    margin-bottom: 8px;
    font-weight: 600;
}
.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #fafafa;
}
.header {
    padding: 16px 24px;
    background: #fff;
    border-bottom: 1px solid #e0e0e0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.chat-area {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.message {
    max-width: 80%;
    padding: 12px 16px;
    border-radius: 12px;
    line-height: 1.5;
    word-wrap: break-word;
    font-size: 14px;
}
.message.user {
    align-self: flex-end;
    background: #007bff;
    color: white;
}
.message.assistant {
    align-self: flex-start;
    background: #fff;
    border: 1px solid #e0e0e0;
    color: #333;
}
.message.has-comment {
    border-left: 3px solid #ffc107;
}
.input-area {
    padding: 16px 24px;
    background: #fff;
    border-top: 1px solid #e0e0e0;
    display: flex;
    gap: 12px;
}
input[type="text"], textarea {
    flex: 1;
    padding: 10px 14px;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    font-size: 14px;
    outline: none;
}
input[type="text"]:focus, textarea:focus {
    border-color: #007bff;
}
button {
    padding: 10px 20px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
}
button:hover { background: #0056b3; }
button:disabled {
    background: #a0c4e8;
    cursor: not-allowed;
}
button.secondary {
    background: #6c757d;
}
button.secondary:hover { background: #545b62; }
.conversation-list {
    flex: 1;
    overflow-y: auto;
    margin-top: 12px;
}
.conv-item {
    padding: 10px 12px;
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 4px;
    font-size: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.conv-item:hover { background: #f0f0f0; }
.conv-item.active { background: #e7f1ff; }
.conv-item button {
    padding: 2px 6px;
    font-size: 12px;
    background: transparent;
    color: #999;
    border: none;
    cursor: pointer;
}
.conv-item button:hover { color: #dc3545; background: transparent; }
.new-chat-btn {
    width: 100%;
    margin-bottom: 8px;
}
.username-section {
    margin-bottom: 16px;
}
.trainer-comment {
    background: #fffbeb;
    border: 1px solid #f59e0b;
    border-radius: 8px;
    padding: 8px 12px;
    margin-top: 8px;
    font-size: 13px;
    color: #92400e;
}
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}
.modal {
    background: white;
    padding: 24px;
    border-radius: 12px;
    width: 500px;
    max-width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}
.modal h3 { margin-bottom: 12px; }
.comment-list { margin: 12px 0; }
.comment-item {
    background: #f8f9fa;
    padding: 8px 12px;
    border-radius: 6px;
    margin-bottom: 8px;
    font-size: 13px;
}
.comment-form {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}
.hidden { display: none !important; }
.user-list-item {
    padding: 10px 12px;
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.user-list-item:hover { background: #f0f0f0; }
.user-list-item.active { background: #e7f1ff; }
.badge {
    font-size: 11px;
    padding: 2px 6px;
    border-radius: 10px;
    background: #e0e0e0;
    color: #555;
}