Igazad van és külön css-el lett így beállítva.

Melyik felelős ezért ebből, mert azt törölném. Az a gombokat is megoldaná, ahogy nézem.

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */
#nav-bar { /* main toolbar containing address bar, search bar, add-on icons */

-moz-box-ordinal-group: 1 !important;

}
#PersonalToolbar { /* bookmarks toolbar */

-moz-box-ordinal-group: 2 !important;

}
#TabsToolbar { /* tab bar */

-moz-box-ordinal-group: 3 !important;

}

#titlebar {display: none !important;}

#main-window {-moz-appearance:none !important;}

:root {
--tab-curve-width: 30px;
}

.arrowscrollbox-scrollbox {
padding-inline-start: 10px !important;
}

/* To be able to see the top border of the tab */
.tab-stack {
margin-top: 2px !important;
}

/* When the window is maximized, the first pinned tab is properly displayed. */
#TabsToolbar {
padding-inline-start: 15px !important;
}

.titlebar-placeholder {
border: none !important;
}

/* Hack to make sure the first tab has enough margin on the left/right due to the curves,
Pinned tabs while in overflow will have custom margin-start calculated by Firefox dynamically, so we
don't want to target that.
*/
.tabbrowser-tab:not([pinned]) {
margin-inline-start: 15px !important;
margin-inline-end: -15px !important;
}

.tabbrowser-tabs:not([overflow]) > .tabbrowser-tab {
margin-inline-start: 15px !important;
margin-inline-end: -15px !important;
}


/* Remove unneeded styles from Photon */
.tabbrowser-tab::before,
.tabbrowser-tab::after {
border: none !important;
}

.tabbrowser-tab > .tab-stack > .tab-background {
background-image: none !important;
-moz-box-orient: horizontal !important;
}

.tab-background[selected="true"] {
border: none !important;
}

.tab-line {
display: none !important;
}

.tab-bottom-line {
display: none !important;
}

/* overlap the tab curves */
.tab-background {
-moz-margin-end: -15px !important;
-moz-margin-start: -15px !important;
}

.tabs-newtab-button {
-moz-margin-end: -15px !important;
}

/* Begin tab background customizations */
.tab-background[selected="true"]::before {
border: none !important;
content: "" !important;
width: 30px !important;
min-height: 30px !important;
background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' xmlns:svg='http://www.w3.org/2000/svg' width='30px' height='31px' preserveAspectRatio='none'><defs><svg:clipPath id='tab-curve-clip-path-start' clipPathUnits='objectBoundingBox'><svg:path d='m 1,0.0625 0.05,0 0,0.938 -1,0 0,-0.028 C 0.32082458,0.95840561 0.4353096,0.81970962 0.48499998,0.5625 0.51819998,0.3905 0.535,0.0659 1,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-curve-clip-path-end' clipPathUnits='objectBoundingBox'><svg:path d='m 0,0.0625 -0.05,0 0,0.938 1,0 0,-0.028 C 0.67917542,0.95840561 0.56569036,0.81970962 0.51599998,0.5625 0.48279998,0.3905 0.465,0.0659 0,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-hover-clip-path' clipPathUnits='objectBoundingBox'><svg:path d='M 0,0.2 0,1 1,1, 1,0.2 z'/></svg:clipPath></defs><foreignObject width='30' height='31' clip-path='url(%23tab-curve-clip-path-start)'><div id='tab-background-fill' style='background-color:rgb(50, 50, 52);background-repeat:no-repeat;height:100%;width:100%;' xmlns='http://www.w3.org/1999/xhtml'></div></foreignObject></svg>") !important;
display: -moz-box !important;
background-repeat: no-repeat !important;
}

.tab-background[selected="true"]::after {
border: none !important;
content: "" !important;
width: 30px !important;
min-height: 30px !important;
background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' xmlns:svg='http://www.w3.org/2000/svg' width='30px' height='31px' preserveAspectRatio='none'><defs><svg:clipPath id='tab-curve-clip-path-start' clipPathUnits='objectBoundingBox'><svg:path d='m 1,0.0625 0.05,0 0,0.938 -1,0 0,-0.028 C 0.32082458,0.95840561 0.4353096,0.81970962 0.48499998,0.5625 0.51819998,0.3905 0.535,0.0659 1,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-curve-clip-path-end' clipPathUnits='objectBoundingBox'><svg:path d='m 0,0.0625 -0.05,0 0,0.938 1,0 0,-0.028 C 0.67917542,0.95840561 0.56569036,0.81970962 0.51599998,0.5625 0.48279998,0.3905 0.465,0.0659 0,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-hover-clip-path' clipPathUnits='objectBoundingBox'><svg:path d='M 0,0.2 0,1 1,1, 1,0.2 z'/></svg:clipPath></defs><foreignObject width='30' height='31' clip-path='url(%23tab-curve-clip-path-end)'><div id='tab-background-fill' style='background-color:rgb(50, 50, 52);background-repeat:no-repeat;height:100%;width:100%;' xmlns='http://www.w3.org/1999/xhtml'></div></foreignObject></svg>") !important;
display: -moz-box !important;
background-repeat: no-repeat !important;
}

.tab-background[selected="true"] > spacer {
background-image:
linear-gradient(rgba(0,0,0,0), rgba(0,0,0,0)),
linear-gradient(
transparent
2px,
rgb(50, 50, 52) 2px,
rgb(50, 50, 52)
),
none !important;
margin-top: 0px !important;
}

#new-tab-button,
.tabs-newtab-button {
width: calc(36px + 30px) !important;
margin-inline-start: 30px;
margin-top: 1px !important;
}

/* Tab hover customizations */

/* Regular tabs */
.tabbrowser-tab:hover > .tab-stack > .tab-background:not([selected=true])::before {
background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' xmlns:svg='http://www.w3.org/2000/svg' width='30px' height='31px' preserveAspectRatio='none'><defs><svg:clipPath id='tab-curve-clip-path-start' clipPathUnits='objectBoundingBox'><svg:path d='m 1,0.0625 0.05,0 0,0.938 -1,0 0,-0.028 C 0.32082458,0.95840561 0.4353096,0.81970962 0.48499998,0.5625 0.51819998,0.3905 0.535,0.0659 1,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-curve-clip-path-end' clipPathUnits='objectBoundingBox'><svg:path d='m 0,0.0625 -0.05,0 0,0.938 1,0 0,-0.028 C 0.67917542,0.95840561 0.56569036,0.81970962 0.51599998,0.5625 0.48279998,0.3905 0.465,0.0659 0,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-hover-clip-path' clipPathUnits='objectBoundingBox'><svg:path d='M 0,0.2 0,1 1,1, 1,0.2 z'/></svg:clipPath></defs><foreignObject width='30' height='31' clip-path='url(%23tab-curve-clip-path-start)'><div id='tab-background-fill' style='background-color:rgba(255, 255, 255, .1);background-repeat:no-repeat;height:100%;width:100%;' xmlns='http://www.w3.org/1999/xhtml'></div></foreignObject></svg>") !important;
display: -moz-box !important;
background-repeat: no-repeat !important;
content: "" !important;
width: 30px !important;
min-height: 30px !important;
background-color: transparent !important;
}

.tabbrowser-tab:hover > .tab-stack > .tab-background:not([selected=true])::after {
background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' xmlns:svg='http://www.w3.org/2000/svg' width='30px' height='31px' preserveAspectRatio='none'><defs><svg:clipPath id='tab-curve-clip-path-start' clipPathUnits='objectBoundingBox'><svg:path d='m 1,0.0625 0.05,0 0,0.938 -1,0 0,-0.028 C 0.32082458,0.95840561 0.4353096,0.81970962 0.48499998,0.5625 0.51819998,0.3905 0.535,0.0659 1,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-curve-clip-path-end' clipPathUnits='objectBoundingBox'><svg:path d='m 0,0.0625 -0.05,0 0,0.938 1,0 0,-0.028 C 0.67917542,0.95840561 0.56569036,0.81970962 0.51599998,0.5625 0.48279998,0.3905 0.465,0.0659 0,0.0625 z'/></svg:clipPath><svg:clipPath id='tab-hover-clip-path' clipPathUnits='objectBoundingBox'><svg:path d='M 0,0.2 0,1 1,1, 1,0.2 z'/></svg:clipPath></defs><foreignObject width='30' height='31' clip-path='url(%23tab-curve-clip-path-end)'><div id='tab-background-fill' style='background-color:rgba(255, 255, 255,.1);background-repeat:no-repeat;height:100%;width:100%;' xmlns='http://www.w3.org/1999/xhtml'></div></foreignObject></svg>") !important;
display: -moz-box !important;
background-repeat: no-repeat !important;
content: "" !important;
width: 30px !important;
min-height: 30px !important;
background-color: transparent !important;
}

.tabbrowser-tab:hover > .tab-stack > .tab-background:not([selected=true]) > spacer {
background-image:
linear-gradient(rgba(0,0,0,0), rgba(0,0,0,0)),
linear-gradient(
transparent
2px,
rgba(255,255,255,.1) 2px,
rgba(255,255,255,.1)
),
none !important;
margin-top: 0px !important;
}


/* Remove window buttons (only needed for a mac I think) */
#titlebar {display: none !important;}
#TabsToolbar .titlebar-placeholder {display: none !important; }

/* hide tab bar if only one tab */
tab:only-of-type {
display:none !important;
}

/* unset the tab bar min-height */
#tabbrowser-tabs, #tabbrowser-tabs > .tabbrowser-arrowscrollbox, #tabbrowser-tabs[positionpinnedtabs] > .tabbrowser-tab[pinned] {
min-height: initial !important;
}

/* set the height on the tabs instead */
tab {
line-height: 32px; height: 32px;
}

/* hide new tab button so tab-bar can collapse */
.tabs-newtab-button {
display: none;
}

/* ...but show it on tab-bar hover */
#tabbrowser-tabs:hover .tabs-newtab-button {
display: block;
}

#TabsToolbar {
min-height: 0px !important;
}

[ Szerkesztve ]

Minden számítógép füsttel működik, ha kimegy belőle, akkor nem működik.