body {
    font-family: 'Segoe UI', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #e0e7ff 0%, #f7f8fa 100%);
    min-height: 100vh;
}

.chat-container {
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    width: 100%;
    max-width: 700px;
    margin: 40px auto 0 auto;
    min-height: 80vh;
    background: #f9fafb;
    box-shadow: 0 8px 32px rgba(60, 80, 120, 0.13);
    border-radius: 20px;
    overflow: hidden;
    border: 1.5px solid #e0e7ef;
    position: relative;
}

.chat-header {
    background: #f1f5fb;
    color: #222;
    padding: 20px 28px 12px 28px;
    font-size: 1.18rem;
    font-weight: 700;
    border-bottom: 1.5px solid #e0e7ef;
    display: flex;
    align-items: center;
    justify-content: space-between;
    letter-spacing: 0.01em;
}
.assistant-status {
    font-weight: 600;
    font-size: 1.08rem;
    display: flex;
    align-items: center;
    gap: 6px;
}
.status-dot {
    color: #22c55e;
    font-size: 1.2em;
    margin-left: 2px;
    text-shadow: 0 0 6px #22c55e44;
}

.chat-box {
    padding: 28px 16px 12px 16px;
    flex-grow: 1;
    overflow-y: auto;
    background: #f7f8fa;
    display: flex;
    flex-direction: column;
    gap: 16px;
    min-height: 320px;
    border-bottom: 1.5px solid #e0e7ef;
}

.message {
    display: flex;
    flex-direction: column;
    margin-bottom: 0;
    padding: 0;
    border-radius: 16px;
    max-width: 80%;
    word-break: break-word;
    box-shadow: 0 2px 8px rgba(60,80,120,0.04);
    border: 1.2px solid #e0e7ef;
    background: #fff;
}

.user-message {
    align-self: flex-end;
    background: #e3f0ff;
    color: #1a237e;
    border-radius: 16px 16px 4px 16px;
    padding: 12px 18px;
    text-align: right;
    font-size: 1rem;
    box-shadow: 0 2px 8px rgba(60,80,120,0.10);
    border: 1.2px solid #b6d4fe;
    word-break: break-word;
}

.bot-message {
    align-self: flex-start;
    background: #fff;
    color: #222;
    border-radius: 16px 16px 16px 4px;
    padding: 12px 18px;
    text-align: left;
    font-size: 1rem;
    border: 1.2px solid #e0e7ef;
    box-shadow: 0 2px 8px rgba(60,80,120,0.04);
}

.input-area {
    display: flex;
    align-items: center;
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
    padding: 18px 18px 18px 18px;
    background: #f9fafb;
    position: sticky;
    bottom: 0;
    z-index: 10;
    box-sizing: border-box;
    border: none;
    gap: 0;
}

.input-group {
    display: flex;
    align-items: center;
    flex: 1 1 auto;
    background: #fff;
    border-radius: 24px;
    padding: 0 16px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
    height: 48px;
    position: relative;
    min-width: 0;
}

.upload-group {
    display: flex;
    align-items: center;
    margin-left: 8px;
    margin-right: 0;
}
.input-area textarea#userInput {
    flex: 1 1 auto;
    min-width: 0;
    padding: 12px 18px;
    border-radius: 24px;
    border: none;
    font-size: 1rem;
    background: #fff;
    outline: none;
    transition: box-shadow 0.2s;
    box-shadow: 0 1px 8px rgba(60,80,120,0.07);
    min-height: 48px;
    max-height: 180px;
    box-sizing: border-box;
    margin: 0;
    resize: none;
    overflow-y: auto;
}
.input-area textarea#userInput:focus {
    box-shadow: 0 2px 12px #2563eb22;
}

.input-area button.send-btn {
    background: #1a8cff;
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(26,140,255,0.15);
    margin-left: 10px;
    margin-right: 0;
    transition: background 0.2s, box-shadow 0.2s;
    flex-shrink: 0;
}
.input-area button.send-btn:hover {
    background: #2563eb;
    box-shadow: 0 4px 16px rgba(26,140,255,0.18);
}

.input-area label.upload-label {
    background: none;
    color: #2563eb;
    border: none;
    padding: 0 8px 0 0;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    transition: background 0.2s;
    margin-right: 4px;
    box-sizing: border-box;
}
.input-area label.upload-label:hover {
    background: #e0e7ff;
}

.input-area input[type="file"] {
    display: none;
}

.file-preview {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0 0 10px 0;
    background: #f1f5fb;
    border-radius: 10px;
    padding: 7px 14px 7px 10px;
    box-shadow: 0 2px 8px rgba(60,80,120,0.04);
    border: 1.2px solid #e0e7ef;
    max-width: 90%;
    min-width: 0;
    flex-shrink: 1;
    overflow: hidden;
    position: absolute;
    left: 50%;
    bottom: 70px;
    transform: translateX(-50%);
    z-index: 20;
}
.file-preview img {
    width: 40px;
    height: 40px;
    object-fit: cover;
    border-radius: 7px;
    box-shadow: 0 2px 8px rgba(60,80,120,0.08);
}
.file-preview .file-info {
    font-size: 14px;
    color: #222;
    margin-left: 7px;
}
.file-preview .delete-file {
    color: #ef4444;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    margin-left: 8px;
    transition: color 0.2s;
}
.file-preview .delete-file:hover {
    color: #b91c1c;
}

.loading-text {
    text-align: center;
    font-size: 17px;
    font-weight: 600;
    color: #2563eb;
    margin: 10px 0 0 0;
    display: none;
    letter-spacing: 0.01em;
    animation: loading-blink 1.2s linear infinite;
}
@keyframes loading-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}


@media (max-width: 900px) {
    .chat-container {
        max-width: 99vw;
        margin: 10px auto 0 auto;
    }
    .chat-header {
        padding: 14px 8px 8px 8px;
        font-size: 1.05rem;
    }
    .chat-box {
        padding: 12px 4px 6px 4px;
    }
    .input-area {
        padding: 10px 4px 10px 4px;
    }
    .file-preview {
        max-width: 98vw;
        left: 50%;
        bottom: 70px;
        transform: translateX(-50%);
    }
}

@media (max-width: 600px) {
    .chat-container {
        max-width: 100vw;
        min-height: 100vh;
        border-radius: 0;
    }
    .chat-header {
        padding: 8px 2px 6px 2px;
        font-size: 0.98rem;
    }
    .chat-box {
        padding: 6px 1px 2px 1px;
        font-size: 0.93rem;
    }
    .input-area {
        padding: 6px 1px 6px 1px;
        gap: 4px;
    }
    .file-preview {
        margin: 4px 0 0 0;
        padding: 5px 5px;
    }
    .message { max-width: 98%; font-size: 14px; }
}