Me ajudem Logo CSS

Jhonny,

O logo não está em CSS, ele é um .svg (Scalable Vector Graphics). Substitua-o no HTML por outro SVG ou por até mesmo uma IMG.

Caso não saiba onde encontrar o logo atual, segue abaixo o código dele (já comece a estudar bastante):

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" preserveAspectRatio="xMidYMid" width="92" height="207" viewBox="0 0 92 207">
 <g id="Texte">
 <path d="M48.8,118.5v-0.9h7.3v0.9l-5.5,2.7l5.5,2.8v0.9h-7.3v-0.9h5.4l-5.4-2.7l5.5-2.7H48.8z"/>
 <path d="M52.8,129.7v2.9h-0.8v-2.9h-2.5v2.9h-0.8v-3.8h7.3v3.8h-0.8v-2.9H52.8z"/>
 <path d="M52.8,137.1v2.9h-0.8v-2.9h-2.5v2.9h-0.8v-3.8h7.3v3.8h-0.8v-2.9H52.8z"/>
 <path d="M48.8,145.8v-0.9h6.5V143h0.8v4.7h-0.8v-1.9H48.8z"/>
 <path d="M52.8,157.3v2.9h-0.8v-2.9h-3.3v-0.9h7.3v3.8h-0.8v-2.9H52.8z"/>
 <path d="M48.8,164.5v-0.9h7.3v2c0,1.6-0.8,2.5-2.1,2.5c-0.8,0-1.5-0.4-1.8-1.1c-0.2-0.4-0.3-0.7-0.3-1.4l-3,2.8v-1.2l3.1-2.8H48.8z M52.5,165.5c0,1.1,0.5,1.7,1.4,1.7c0.9,0,1.4-0.5,1.4-1.6v-1.1h-2.8V165.5z"/>
 <path d="M48.8,172.8v-0.9h7.3v0.9H48.8z"/>
 <path d="M52.8,177.6v2.9h-0.8v-2.9h-2.5v2.9h-0.8v-3.8h7.3v3.8h-0.8v-2.9H52.8z"/>
 <path d="M48.8,185.1v-0.9h7.3v0.8l-5.5,3.9h5.5v0.9h-7.3v-0.8l5.6-3.9H48.8z"/>
 <path d="M56.1,193.9v1.9c0,2.2-1.3,3.5-3.6,3.5c-1.2,0-2.3-0.4-2.9-1.2c-0.6-0.6-0.8-1.5-0.8-2.6v-1.8H56.1zM49.5,194.8v0.3c0,1.2,0.1,1.8,0.6,2.3c0.5,0.7,1.3,1,2.4,1c1.8,0,2.8-0.9,2.8-2.6v-1H49.5z"/>
 <path d="M50.7,203.4c-0.8,0-1.3,0.5-1.3,1.3c0,0.8,0.5,1.4,1.2,1.4c0.6,0,0.9-0.3,1.3-1.5c0.3-0.9,0.4-1.2,0.7-1.5c0.3-0.4,0.8-0.6,1.4-0.6c1.2,0,2.1,0.9,2.1,2.2c0,1.3-0.8,2.1-2.1,2.2V206c0.4,0,0.6-0.1,0.8-0.2c0.3-0.2,0.5-0.6,0.5-1.1c0-0.7-0.5-1.2-1.2-1.2c-0.4,0-0.7,0.2-0.8,0.4c-0.2,0.2-0.3,0.4-0.5,1.2c-0.3,0.8-0.5,1.2-0.8,1.5c-0.3,0.3-0.8,0.5-1.3,0.5c-1.3,0-2.1-0.9-2.1-2.3c0-0.9,0.3-1.6,1-2c0.3-0.2,0.6-0.3,1-0.3h0.2V203.4z"/>
 <path d="M41.5,122.3v-3.2H40v3.2h-1.3v-3.2H37v3.2h-1.4v-4.9h7.3v4.9H41.5z"/>
 <path d="M35.6,131.8v-1.9l1.2-0.3v-2.2l-1.2-0.3v-1.8l7.4,2.1v2.1L35.6,131.8z M41.3,128.6l-3.2-0.8v1.5L41.3,128.6z"/>
 <path d="M41.5,139.5v-1.9h-5.9v-1.7h5.9V134h1.4v5.5H41.5z"/>
 <path d="M41.5,153v-3.1H40v3.1h-1.4v-3.1h-3v-1.7h7.3v4.8H41.5z"/>
 <path d="M42.9,159.5c0,1-0.1,1.5-0.5,2c-0.4,0.5-0.9,0.7-1.6,0.7c-1.1,0-1.8-0.6-2.1-1.9l-3.2,2.1v-2.2l3.4-2h-3.4v-1.7h7.3V159.5z M39.8,158.8c0,0.6,0,0.8,0.1,1.1c0.1,0.3,0.4,0.5,0.7,0.5s0.6-0.2,0.7-0.5c0.1-0.3,0.1-0.5,0.1-1.1v-0.6h-1.8V158.8z"/>
 <path d="M41.5,170.6v-3.2H40v3.2h-1.3v-3.2H37v3.2h-1.4v-4.9h7.3v4.9H41.5z"/>
 <path d="M37.8,175.6c-0.7,0-1,0.4-1,0.9c0,0.5,0.3,0.8,0.7,0.8c0.3,0,0.5-0.1,0.6-0.4c0.2-0.3,0.2-0.3,0.8-1.4c0.5-1.1,1-1.4,2-1.4c1.4,0,2.2,1,2.2,2.6c0,0.8-0.2,1.4-0.6,1.8c-0.2,0.2-0.5,0.4-1,0.5l-0.6-1.6c0.6-0.1,0.8-0.4,0.8-0.9c0-0.4-0.3-0.7-0.6-0.7c-0.4,0-0.7,0.3-0.9,0.9c-0.4,0.9-0.5,1.1-0.7,1.4c-0.4,0.6-1,0.9-1.7,0.9c-0.7,0-1.3-0.3-1.7-0.8c-0.4-0.5-0.6-1.1-0.6-1.9c0-0.9,0.2-1.5,0.7-1.9c0.3-0.2,0.5-0.4,1.1-0.5L37.8,175.6z"/>
 <path d="M40.1,186.6h2.8v1.7h-7.3v-1.7h3.2v-2.3h-3.2v-1.7h7.3v1.7h-2.8V186.6z"/>
 </g>
 <g id="Logo">
 <path id="twentyheight" d="M50.9,47.4c0.3-0.2,0.5-0.4,0.7-0.5c0.2-0.1,0.4-0.3,0.7-0.5c2.9-1.9,9.7-6.4,9.7-13.3c0-5.8-5-10.6-11-10.6c-5.3,0-9.7,3.6-10.8,8.3c-4.6,0.2-8.3,3.8-8.3,8.3H34c0-3.2,2.6-5.8,5.9-6.1c0,0,0,0,0,0c0,2.6,1.2,5.2,3.5,7.9l1.7-1.4c-1.9-2.2-2.9-4.3-3-6.3c2.8,0.7,4.9,3.1,4.9,5.9c0,1.4-0.6,2.8-1.8,4.3L30.6,61.1h9.6c1.1,4.8,5.5,8.3,10.8,8.3c6.1,0,11-4.7,11-10.6c0-4.7-3.9-8.8-7.2-11.4l-1.4,1.7c2.4,1.9,6.4,5.6,6.4,9.6c0,4.6-4,8.4-8.8,8.4c-4.1,0-7.5-2.6-8.5-6.1h5.7v-2.2h-6c0,0,0,0,0,0C42.1,53.1,48,49.3,50.9,47.4z M39.9,58.9C39.9,58.9,39.9,58.9,39.9,58.9l-4.6,0L46.9,45l0,0c1.5-1.9,2.2-3.8,2.2-5.7c0-4-2.9-7.3-6.8-8.1c1-3.6,4.4-6.3,8.6-6.3c4.9,0,8.8,3.8,8.8,8.4c0,5.7-5.9,9.6-8.7,11.4c-0.3,0.2-0.5,0.3-0.7,0.5c-0.2,0.1-0.4,0.3-0.7,0.5C46.7,47.5,39.9,52,39.9,58.9z"/>
 <path id="l" d="M27.8,43.3h-1.5v7.1h0.7h0.7h1.7v-1.5h-1.7V43.3z"/>
 <path id="e" d="M33.3,50.4H35v-1.5h-1.7v-1.3H35v-1.5h-1.7v-1.3H35v-1.5h-1.7h-0.7h-0.7v7.1h0.7H33.3z"/>
 <ellipse cx="46" cy="46" rx="45" ry="45"/>
 </g>
</svg>

Pra criar um novo logo em .SVG, você precisa utilizar o Adobe Illustrator (exemplo) e salvar o seu arquivo como .SVG. Existem milhares de tutoriais na internet ensinando isso.

Bons estudos e boa sorte!