/* author: Marina Osadcha */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    font-family: "Roboto", sans-serif;
    color: rgb(85, 75, 85);
    background-color: rgb(255, 255, 255);
    overflow: hidden;
}
h1 {
    padding: 50px 0;
    font-size: 45px;
    text-align: center;
    color: rgb(54, 56, 55);
}
:active,
:hover,
:focus {
    outline: 0 !important;
    outline-offset: 0;
}
::before,
::after {
    position: absolute;
    content: "";
}

.btn-holder {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    max-width: 1000px;
    margin: 10px auto 35px;
}
.btn {
    position: relative;
    display: inline-block;
    width: auto;
    height: auto;
    background-color: transparent;
    border: none;
    cursor: pointer;
    margin: 0px 25px 15px;
    min-width: 150px;
}
.btn span {
    position: relative;
    display: inline-block;
    font-size: 14px;
    font-weight: bold;
    letter-spacing: 2px;
    text-transform: uppercase;
    top: 0;
    left: 0;
    width: 100%;
    padding: 15px 20px;
    transition: 0.3s;
}

/*--- btn-1 ---*/
.btn-1::before {
    background-color: rgb(28, 31, 30);
    transition: 0.3s ease-out;
}
.btn-1 span {
    color: rgb(255, 255, 255);
    border: 1px solid rgb(28, 31, 30);
    transition: 0.2s 0.1s;
}
.btn-1 span:hover {
    color: rgb(28, 31, 30);
    transition: 0.2s 0.1s;
}

/* 1.hover-filled-slide-down */
.btn.hover-filled-slide-down::before {
    bottom: 0;
    left: 0;
    right: 0;
    height: 100%;
    width: 100%;
}
.btn.hover-filled-slide-down:hover::before {
    height: 0%;
}

/* 2.hover-filled-slide-up */
.btn.hover-filled-slide-up::before {
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    width: 100%;
}
.btn.hover-filled-slide-up:hover::before {
    height: 0%;
}

/* 3.hover-filled-slide-left */
.btn.hover-filled-slide-left::before {
    top: 0;
    bottom: 0;
    left: 0;
    height: 100%;
    width: 100%;
}
.btn.hover-filled-slide-left:hover::before {
    width: 0%;
}

/* 4. hover-filled-slide-right */
.btn.hover-filled-slide-right::before {
    top: 0;
    bottom: 0;
    right: 0;
    height: 100%;
    width: 100%;
}
.btn.hover-filled-slide-right:hover::before {
    width: 0%;
}

/* 5. hover-filled-opacity */
.btn.hover-filled-opacity::before {
    top: 0;
    bottom: 0;
    right: 0;
    height: 100%;
    width: 100%;
    opacity: 1;
}
.btn.hover-filled-opacity:hover::before {
    opacity: 0;
}

/*--- btn-2 ---*/
.btn-2::before {
    background-color: rgb(28, 31, 30);
    transition: 0.3s ease-out;
}
.btn-2 span {
    color: rgb(28, 31, 30);
    border: 1px solid rgb(28, 31, 30);
    transition: 0.2s;
}
.btn-2 span:hover {
    color: rgb(255, 255, 255);
    transition: 0.2s 0.1s;
}

/* 6. hover-slide-down */
.btn.hover-slide-down::before {
    top: 0;
    left: 0;
    right: 0;
    height: 0%;
    width: 100%;
}
.btn.hover-slide-down:hover::before {
    height: 100%;
}

/* 7. hover-slide-up */
.btn.hover-slide-up::before {
    bottom: 0;
    left: 0;
    right: 0;
    height: 0%;
    width: 100%;
}
.btn.hover-slide-up:hover::before {
    height: 100%;
}

/* 8. hover-slide-left */
.btn.hover-slide-left::before {
    top: 0;
    bottom: 0;
    right: 0;
    height: 100%;
    width: 0%;
}
.btn.hover-slide-left:hover::before {
    width: 100%;
}

/* 9. hover-slide-right */
.btn.hover-slide-right::before {
    top: 0;
    bottom: 0;
    left: 0;
    height: 100%;
    width: 0%;
}
.btn.hover-slide-right:hover::before {
    width: 100%;
}

/* 10. hover-opacity */
.btn.hover-opacity::before {
    top: 0;
    bottom: 0;
    right: 0;
    height: 100%;
    width: 100%;
    opacity: 0;
}
.btn.hover-opacity:hover::before {
    opacity: 1;
}

/*--- btn-3 ---*/
.btn-3 {
    padding: 5px;
}
.btn-3 span {
    color: rgb(255, 255, 255);
    background-color: rgb(54, 56, 55);
}
.btn-3::before,
.btn-3::after {
    background: transparent;
    z-index: 2;
}

/* 11. hover-border-1 */
.btn.hover-border-1::before,
.btn.hover-border-1::after {
    width: 10%;
    height: 25%;
    transition: 0.35s;
}
.btn.hover-border-1::before {
    top: 0;
    left: 0;
    border-left: 1px solid rgb(28, 31, 30);
    border-top: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-1::after {
    bottom: 0;
    right: 0;
    border-right: 1px solid rgb(28, 31, 30);
    border-bottom: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-1:hover::before,
.btn.hover-border-1:hover::after {
    width: 99%;
    height: 98%;
}

/* 12. hover-border-2 */
.btn.hover-border-2::before,
.btn.hover-border-2::after {
    width: 10%;
    height: 25%;
    transition: 0.35s;
}
.btn.hover-border-2::before {
    bottom: 0;
    left: 0;
    border-left: 1px solid rgb(28, 31, 30);
    border-bottom: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-2::after {
    top: 0;
    right: 0;
    border-right: 1px solid rgb(28, 31, 30);
    border-top: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-2:hover::before,
.btn.hover-border-2:hover::after {
    width: 99%;
    height: 99%;
}

/* 13. hover-border-3 */
.btn.hover-border-3::before,
.btn.hover-border-3::after {
    width: 0%;
    height: 0%;
    opacity: 0;
    transition: width 0.2s 0.15s linear, height 0.15s linear, opacity 0s 0.35s;
}
.btn.hover-border-3::before {
    top: 0;
    right: 0;
    border-top: 1px solid rgb(28, 31, 30);
    border-left: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-3::after {
    bottom: 0;
    left: 0;
    border-bottom: 1px solid rgb(28, 31, 30);
    border-right: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-3:hover::before,
.btn.hover-border-3:hover::after {
    width: 100%;
    height: 99%;
    opacity: 1;
    transition: width 0.2s linear, height 0.15s 0.2s linear, opacity 0s;
}

/* 14. hover-border-4 */
.btn.hover-border-4::before,
.btn.hover-border-4::after {
    width: 0%;
    height: 0%;
    opacity: 0;
    transition: width 0.2s linear, height 0.15s 0.2s ease-out, opacity 0s 0.35s;
}
.btn.hover-border-4::before {
    bottom: 0;
    left: -1px;
    border-top: 1px solid rgb(28, 31, 30);
    border-left: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-4::after {
    top: 0;
    right: 0;
    border-bottom: 1px solid rgb(28, 31, 30);
    border-right: 1px solid rgb(28, 31, 30);
}
.btn.hover-border-4:hover::before,
.btn.hover-border-4:hover::after {
    width: 100%;
    height: 99%;
    opacity: 1;
    transition: width 0.2s 0.15s ease-out, height 0.15s ease-in, opacity 0s;
}

/* 15. hover-border-5 */
.btn.hover-border-5::before,
.btn.hover-border-5::after {
    width: 0%;
    height: 0%;
    opacity: 0;
}
.btn.hover-border-5::before {
    top: 0;
    right: 0;
    border-top: 1px solid rgb(28, 31, 30);
    border-left: 1px solid rgb(28, 31, 30);
    transition: width 0.2s 0.5s ease-out, height 0.15s 0.35s linear, opacity 0s 0.7s;
}
.btn.hover-border-5::after {
    bottom: 0;
    left: 0px;
    border-bottom: 1px solid rgb(28, 31, 30);
    border-right: 1px solid rgb(28, 31, 30);
    transition: width 0.2s 0.15s linear, height 0.15s ease-in, opacity 0s 0.35s;
}
.btn.hover-border-5:hover::before,
.btn.hover-border-5:hover::after {
    width: 100%;
    height: 96%;
    opacity: 1;
}
.btn.hover-border-5:hover::before {
    transition: width 0.2s ease-in, height 0.15s 0.2s linear, opacity 0s; /* 1,2 */
}
.btn.hover-border-5:hover::after {
    transition: width 0.2s 0.35s linear, height 0.15s 0.5s ease-out, opacity 0s 0.3s;
}

/*--- btn-4 ---*/
.btn-4 span {
    color: rgb(28, 31, 30);
    background-color: rgb(245, 245, 245);
}
.btn-4 span:hover {
    color: rgb(54, 56, 55);
}
.btn-4::before,
.btn-4::after {
    width: 15%;
    height: 2px;
    background-color: rgb(54, 56, 55);
    z-index: 2;
}

/* 16. hover-border-6 */
.btn.hover-border-6::before,
.btn.hover-border-6::after {
    top: 0;
    transition: width 0.2s 0.35s ease-out;
}
.btn.hover-border-6::before {
    right: 50%;
}
.btn.hover-border-6::after {
    left: 50%;
}
.btn.hover-border-6:hover::before,
.btn.hover-border-6:hover::after {
    width: 50%;
    transition: width 0.2s ease-in;
}

.btn.hover-border-6 span::before,
.btn.hover-border-6 span::after {
    width: 0%;
    height: 0%;
    background: transparent;
    opacity: 0;
    z-index: 2;
    transition: width 0.2s ease-in, height 0.15s 0.2s linear, opacity 0s 0.35s;
}
.btn.hover-border-6 span::before {
    top: 0;
    left: 0;
    border-left: 2px solid rgb(54, 56, 55);
    border-bottom: 2px solid rgb(54, 56, 55);
}
.btn.hover-border-6 span::after {
    top: 0;
    right: 0;
    border-right: 2px solid rgb(54, 56, 55);
    border-bottom: 2px solid rgb(54, 56, 55);
}
.btn.hover-border-6 span:hover::before,
.btn.hover-border-6 span:hover::after {
    width: 50%;
    height: 96%;
    opacity: 1;
    transition: height 0.2s 0.2s ease-in, width 0.2s 0.4s linear, opacity 0s 0.2s;
}

/* 17. hover-border-7 */
.btn.hover-border-7::before,
.btn.hover-border-7::after {
    bottom: 0;
    transition: width 0.2s 0.35s ease-out;
}
.btn.hover-border-7::before {
    right: 50%;
}
.btn.hover-border-7::after {
    left: 50%;
}
.btn.hover-border-7:hover::before,
.btn.hover-border-7:hover::after {
    width: 50%;
    transition: width 0.2s ease-in;
}

.btn.hover-border-7 span::before,
.btn.hover-border-7 span::after {
    width: 0%;
    height: 0%;
    background: transparent;
    opacity: 0;
    z-index: 2;
    transition: width 0.2s ease-in, height 0.15s 0.2s linear, opacity 0s 0.35s;
}
.btn.hover-border-7 span::before {
    bottom: 0;
    left: 0;
    border-left: 2px solid rgb(54, 56, 55);
    border-top: 2px solid rgb(54, 56, 55);
}
.btn.hover-border-7 span::after {
    bottom: 0;
    right: 0;
    border-right: 2px solid rgb(54, 56, 55);
    border-top: 2px solid rgb(54, 56, 55);
}
.btn.hover-border-7 span:hover::before,
.btn.hover-border-7 span:hover::after {
    width: 50%;
    height: 96%;
    opacity: 1;
    transition: height 0.2s 0.2s ease-in, width 0.2s 0.4s linear, opacity 0s 0.2s;
}

/* 18. hover-border-8 */
.btn.hover-border-8::before,
.btn.hover-border-8::after {
    bottom: 0;
    width: 15%;
    transition: width 0.2s 0.35s ease-out;
}
.btn.hover-border-8::before {
    right: 50%;
}
.btn.hover-border-8::after {
    left: 50%;
}
.btn.hover-border-8:hover::before {
    width: 50%;
    transition: width 0.2s ease-in;
}
.btn.hover-border-8:hover::after {
    width: 50%;
    transition: width 0.1s ease-in;
}

.btn.hover-border-8 span::before,
.btn.hover-border-8 span::after {
    width: 0%;
    height: 0%;
    bottom: 0;
    background: transparent;
    opacity: 0;
    z-index: 2;
}
.btn.hover-border-8 span::before {
    left: 0%;
    border-left: 2px solid rgb(54, 56, 55);
    transition: height 0.25s ease-in, opacity 0s 0.35s;
}
.btn.hover-border-8 span:hover::before {
    height: 96%;
    opacity: 1;
    transition: height 0.25s 0.2s ease-out, opacity 0s 0.2s;
}
.btn.hover-border-8 span::after {
    right: 0%;
    border-right: 2px solid rgb(54, 56, 55);
    border-top: 2px solid rgb(54, 56, 55);
    transition: width 0.2s ease-in, height 0.15s 0.2s linear, opacity 0s 0.35s;
}
.btn.hover-border-8 span:hover::after {
    width: 99%;
    height: 96%;
    opacity: 1;
    transition: height 0.15s 0.1s linear, width 0.2s 0.25s linear, opacity 0s 0.1s;
}

/* 19. hover-border-9 */
.btn.hover-border-9::before,
.btn.hover-border-9::after {
    bottom: 0;
    width: 15%;
    transition: width 0.2s 0.35s ease-out;
}
.btn.hover-border-9::before {
    right: 50%;
}
.btn.hover-border-9::after {
    left: 50%;
}
.btn.hover-border-9:hover::before {
    width: 50%;
    transition: width 0.1s ease-in;
}
.btn.hover-border-9:hover::after {
    width: 50%;
    transition: width 0.2s ease-in;
}

.btn.hover-border-9 span::before,
.btn.hover-border-9 span::after {
    width: 0%;
    height: 0%;
    bottom: 0;
    background: transparent;
    opacity: 0;
    z-index: 2;
}
.btn.hover-border-9 span::after {
    right: 0%;
    border-right: 2px solid rgb(54, 56, 55);
    transition: height 0.25s ease-in, opacity 0s 0.35s;
}
.btn.hover-border-9 span:hover::after {
    height: 96%;
    opacity: 1;
    transition: height 0.25s 0.2s ease-out, opacity 0s 0.2s;
}
.btn.hover-border-9 span::before {
    left: 0%;
    border-left: 2px solid rgb(54, 56, 55);
    border-top: 2px solid rgb(54, 56, 55);
    transition: width 0.2s ease-in, height 0.15s 0.2s linear, opacity 0s 0.35s;
}
.btn.hover-border-9 span:hover::before {
    width: 98.5%;
    height: 96%;
    opacity: 1;
    transition: height 0.15s 0.1s linear, width 0.2s 0.25s linear, opacity 0s 0.1s;
}

/* 20. hover-border-10 */
.btn.hover-border-10::before,
.btn.hover-border-10::after {
    left: 0%;
    height: 30%;
    width: 2px;
    transition: height 0.2s 0.35s ease-out;
}
.btn.hover-border-10::before {
    top: 50%;
}
.btn.hover-border-10::after {
    bottom: 50%;
}
.btn.hover-border-10:hover::before {
    height: 50%;
    transition: height 0.2s ease-in;
}
.btn.hover-border-10:hover::after {
    height: 50%;
    transition: height 0.1s ease-in;
}

.btn.hover-border-10 span::before,
.btn.hover-border-10 span::after {
    width: 0%;
    height: 0%;
    background: transparent;
    opacity: 0;
    z-index: 2;
}
.btn.hover-border-10 span::after {
    bottom: 0;
    left: 0%;
    border-bottom: 2px solid rgb(54, 56, 55);
    transition: width 0.25s ease-in, opacity 0s 0.35s;
}
.btn.hover-border-10 span:hover::after {
    width: 100%;
    opacity: 1;
    transition: width 0.25s 0.2s ease-out, opacity 0s 0.2s;
}
.btn.hover-border-10 span::before {
    top: 0%;
    left: 0%;
    border-top: 2px solid rgb(54, 56, 55);
    border-right: 2px solid rgb(54, 56, 55);
    transition: height 0.15s ease-in, width 0.2s 0.15s linear, opacity 0s 0.35s;
}
.btn.hover-border-10 span:hover::before {
    width: 98.5%;
    height: 96%;
    opacity: 1;
    transition: width 0.2s 0.1s linear, height 0.15s 0.3s ease-out, opacity 0s 0.1s;
}

/*--- btn-5 ---*/
.btn-5 span {
    color: rgb(28, 31, 30);
    border: 2px solid rgb(249, 211, 27);
    transition: 0.2s;
}
.btn-5 span:hover {
    background-color: rgb(245, 245, 245);
}

/* 21. hover-border-11 */
.btn.hover-border-11::before,
.btn.hover-border-11::after {
    width: 100%;
    height: 2px;
    background-color: rgb(54, 56, 55);
    z-index: 2;
    transition: 0.35s;
}
.btn.hover-border-11::before {
    top: 0;
    right: 0;
}
.btn.hover-border-11::after {
    bottom: 0;
    left: 0;
}
.btn.hover-border-11:hover::before,
.btn.hover-border-11:hover::after {
    width: 0%;
    transition: 0.2s 0.2s ease-out;
}

.btn.hover-border-11 span::before,
.btn.hover-border-11 span::after {
    width: 2px;
    height: 100%;
    background-color: rgb(54, 56, 55);
    z-index: 2;
    transition: 0.25s;
}
.btn.hover-border-11 span::before {
    bottom: 0;
    right: -2px;
}
.btn.hover-border-11 span::after {
    top: 0;
    left: -2px;
}
.btn.hover-border-11 span:hover::before,
.btn.hover-border-11 span:hover::after {
    height: 0%;
}
