@media only screen and (max-width: 600px) {
    .message-sender-nickname{
        font-size:2.5vh;
        font-weight:bold;
        text-align:left;
    }

    .message-text-data{
        font-size:1.5vh;
        text-align:left;
    }

    .message-block{
        width:100%;
        height: fit-content;
        padding:1vh;
    }

    .button-holder{
        display:flex;
        flex-direction:row;
    }

    .message-button{
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        border-width: 2px;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        border-style: solid;
        border-color: black;
        border-radius: 2.5vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
    }

    .message-button:hover{
        background-color: grey;
    }

    /* ============================================
       HYBRID SIGNATURE CERTIFICATION STYLES
       Mobile Portrait
       ============================================ */
    
    .message-sign-button {
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        border-width: 2px;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        border-style: solid;
        border-color: #888;
        border-radius: 2.5vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        color: #888;
        transition: all 0.2s ease;
    }

    .message-sign-button:hover {
        background-color: #e0e0e0;
        border-color: #666;
        color: #666;
    }

    .message-signed-badge {
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        color: #8b5cf6;  /* Violet for signed */
        animation: signature-pulse-mobile 2s infinite;
    }

    @keyframes signature-pulse-mobile {
        0%, 100% { opacity: 1; transform: scale(1); }
        50% { opacity: 0.8; transform: scale(0.95); }
    }

    .message-unsign-button {
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        border-width: 2px;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        border-style: solid;
        border-color: #f59e0b;
        border-radius: 2.5vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        color: #f59e0b;  /* Orange for un-sign */
        transition: all 0.2s ease;
    }

    .message-unsign-button:hover {
        background-color: #fef3c7;
        border-color: #d97706;
        color: #d97706;
    }

    .message-revoked-badge {
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        color: #ef4444;  /* Red for revoked */
    }

    .message-export-button {
        height: 5vh;
        width: 5vh;
        font-size: 3vh;
        border-width: 2px;
        margin-left: 1vh;
        margin-right: 1vh;
        margin-top:1vh;
        border-style: solid;
        border-color: #10b981;
        border-radius: 2.5vh;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        color: #10b981;  /* Green for export */
        transition: all 0.2s ease;
    }

    .message-export-button:hover {
        background-color: #d1fae5;
        border-color: #059669;
        color: #059669;
    }

    /* Message block states */
    .message-block[data-signature-state="signed"] {
        border-left: 3px solid #8b5cf6;
        background: linear-gradient(to right, rgba(139, 92, 246, 0.05), transparent);
    }

    .message-block[data-signature-state="revoked"] {
        border-left: 3px solid #ef4444;
        background: linear-gradient(to right, rgba(239, 68, 68, 0.05), transparent);
    }
}