/* Custom scrollbar */
::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: #9ca3af;
}

/* Auto-resize textarea */
#message-input {
    line-height: 1.5;
}

/* File preview thumbnails */
.file-thumb {
    position: relative;
    width: 64px;
    height: 64px;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid #e5e7eb;
}
.file-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.file-thumb .remove-btn {
    position: absolute;
    top: -4px;
    right: -4px;
    width: 18px;
    height: 18px;
    background: #ef4444;
    color: white;
    border-radius: 50%;
    font-size: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border: 2px solid white;
}

/* Message bubble animation */
.message-bubble-enter {
    animation: slideUp 0.2s ease-out;
}
@keyframes slideUp {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Toast notification */
.toast {
    position: fixed;
    top: 16px;
    right: 16px;
    background: #1f2937;
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 14px;
    z-index: 100;
    animation: fadeInOut 3s ease-in-out;
}
@keyframes fadeInOut {
    0% { opacity: 0; transform: translateY(-8px); }
    10% { opacity: 1; transform: translateY(0); }
    80% { opacity: 1; }
    100% { opacity: 0; }
}