body { font-size: 16px; }
.page-container { padding: 0 5px; }
.main-columns { flex-direction: column !important; gap: 0 !important; }
.main-col, .main-col-left { width: 100% !important; max-width: 100% !important; min-width: 0 !important; }
.main-columns > .main-col > .box { margin: 10px 0 !important; }
.header { font-size: 20px; border-radius: 14px 14px 0 0; padding: 14px 0 8px 0; }
.logo { font-size: 18px; gap: 8px; }
.menu { flex-wrap: wrap; gap: 4px; padding: 6px 0; }
.menu a { font-size: 13px; padding: 6px 12px; border-radius: 8px; margin: 0 1px; min-height: 32px; gap: 4px; display: inline-flex; align-items: center; }
.menu a i { font-size: 12px; }
.box, .login-box { max-width: 100%; border-radius: 14px; margin: 12px auto; padding: 0; }

@media (max-width: 450px) {
    .menu a {
        font-size: 0 !important;
        padding: 8px !important;
        min-width: 40px !important;
        justify-content: center !important;
    }
    .menu a i {
        font-size: 16px !important;
        margin: 0 !important;
    }
}
.box-title { font-size: 16px; padding: 14px 10px; border-radius: 14px 14px 0 0; }
.chat-list { padding: 14px 6px; min-height: 120px; border-radius: 0 0 14px 14px; }
.chat-item { padding: 10px 0; border-radius: 12px; }
.avatar { width: 38px; height: 38px; margin-right: 8px; border-width: 2px; min-width: 36px; min-height: 36px; }
.username { font-size: 15px; margin-right: 6px; }
.status-dot { width: 10px; height: 10px; margin-right: 4px; }
.time { font-size: 12px; margin-left: 6px; }
.message { font-size: 16px; margin-top: 3px; }
.chat-form-custom { padding: 10px; gap: 8px; border-radius: 0 0 14px 14px; }
.chat-form-custom input[type=text] { font-size: 15px; padding: 10px 12px; border-radius: 8px; min-height: 36px; }
.chat-form-custom button { font-size: 15px; padding: 0 18px; border-radius: 8px; min-height: 36px; }
.category-box { border-radius: 14px; margin-top: 12px; }
.category-list { padding: 10px 4px; gap: 10px; }
.category-item { font-size: 15px; padding: 12px 12px; border-radius: 10px; gap: 8px; min-height: 36px; }
.category-icon { font-size: 16px; min-width: 20px; }
.download-box { border-radius: 14px; margin-bottom: 12px; }
.download-list { gap: 8px; padding: 10px 0 8px 0; }
.download-btn { font-size: 15px; padding: 8px 18px; border-radius: 10px; min-height: 36px; }
.compact-download { border-radius: 10px; }
.compact-download-list { gap: 6px; padding: 6px 0 5px 0; }
.compact-btn { font-size: 13px !important; padding: 5px 12px !important; border-radius: 7px !important; min-height: 36px; }
.stats { font-size: 15px; border-radius: 0 0 14px 14px; padding: 12px 6px; }
.profile-box { max-width: 100%; border-radius: 10px; padding: 12px 4px 12px 4px; }
.profile-box button { font-size: 14px; padding: 7px 14px; border-radius: 8px; min-height: 36px; }
.profile-box input[type="password"] { font-size: 14px; padding: 8px 10px; border-radius: 8px; min-height: 36px; }
.profile-header { flex-direction: column; gap: 6px; text-align: center; }
.profile-info { text-align: center; }
.profile-avatar { width: 38px; height: 38px; }
.profile-username { font-size: 15px; }
.profile-section { padding: 10px 3px; border-radius: 8px; }
.profile-section-title { font-size: 13px; }
.profile-logout-btn { font-size: 14px; padding: 7px 14px; border-radius: 8px; min-height: 36px; }
.admin-table th, .admin-table td { font-size: 13px; padding: 7px 4px; }
.admin-action { font-size: 14px; padding: 7px 12px; border-radius: 8px; min-height: 36px; }
#toast.toast, .toast { font-size: 14px; padding: 10px 18px; border-radius: 10px; min-width: 140px; }
#delete-modal { min-width: 200px; padding: 16px 12px 12px 12px; border-radius: 12px; }
#delete-modal .modal-title { font-size: 15px; margin-bottom: 8px; }
#delete-modal .modal-desc { font-size: 13px; margin-bottom: 12px; }
#delete-modal .modal-btn { font-size: 14px; padding: 7px 16px; border-radius: 8px; min-height: 36px; }
.topic-title {
    /* reset lại cho PC nếu bị ảnh hưởng */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-size: 16px;
    font-weight: 600;
    color: #2b7a78;
    margin-bottom: 8px;
    text-decoration: none;
    display: block;
}
.topic-content {
    flex: 1;
    min-width: 0;
}

@media (max-width: 700px) {
    .topic-item {
        flex-direction: row !important;
        align-items: flex-start !important;
        gap: 10px !important;
        padding: 12px 6px !important;
    }
    .topic-avatar {
        width: 36px !important;
        height: 36px !important;
        min-width: 36px !important;
        min-height: 36px !important;
    }
    .topic-content {
        display: flex !important;
        flex-direction: column !important;
        justify-content: center !important;
        min-width: 0 !important;
        width: 100% !important;
        padding: 0 !important;
    }
    .topic-title {
        display: block !important;
        white-space: normal !important;
        word-break: break-word !important;
        overflow: visible !important;
        text-overflow: unset !important;
        font-size: 15px !important;
        color: #2b7a78 !important;
        font-weight: bold !important;
        background: none !important;
        min-height: unset !important;
        margin-bottom: 6px !important;
        letter-spacing: normal !important;
        text-align: left !important;
    }
    .topic-preview {
        font-size: 13px !important;
        -webkit-line-clamp: 1 !important;
        margin-bottom: 4px !important;
    }
    .topic-meta {
        gap: 8px !important;
        font-size: 12px !important;
    }
    .topic-stats, .topic-stat {
        display: none !important;
    }
}