*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}
body {
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #fff;
}

.flip-card {
    background-color: transparent;
    width: 400px;
    height: 550px;
    margin:0 auto;
    perspective: 1000px;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s;
    transform-style: preserve-3d;
    box-shadow: 0px 4px 8px rgba(0, 0, 0, 0.2);
}

.flip-card-inner.flipped {
    transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    padding: 30px;
}

.flip-card-front {
    background-color: #fff;
    color: black;
    padding: 30px;
    box-sizing: border-box;
}

.input-group {
    display: flex;
    align-items: center;
    background: #ECF0F1;
    margin: 15px 0;
    padding: 12px 30px 12px 30px;
    border-radius: 30px;
}

.input-group i {
    margin-right: 10px;
    color: #1ABC9C;
}

.input-group input {
    border: none;
    outline: none;
    background: transparent;
    flex: 1;
    padding: 10px 20px 10px 20px;
    font-size: 16px;
    border-radius: 30px;
}


.fitness-text {
    margin-top: 20px;
    color: #34495E;
    font-size: 14px;
}


.flip-card-back {
    background-color: #1ABC9C;
    color: white;
    transform: rotateY(180deg);
    padding: 30px;
    box-sizing: border-box;
}


.fitness-text-register {
    margin-top: 20px;
    color: #34495E;
    font-size: 14px;
}

.dumbbell-icon {
    margin-top: 20px;
    font-size: 40px;
    color: #1ABC9C;
}

#dumbbell-icon-register{
    color: white;
}


.fitness-text-register {
    font-size: 16px;
    text-decoration: none;
    color: #fff;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.fitness-text-register:hover {
    color: #16A085;
}


@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    50% { transform: translateX(5px); }
    75% { transform: translateX(-5px); }
}

.shake {
    animation: shake 0.3s ease-in-out;
}
#headingLogin{
    background: linear-gradient(90deg, #00c853, #0c7bd1);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: bold;
}

body.dark-mode {
    background-color: #121212;
    color: #E0E0E0;
}

body.dark-mode .flip-card-front {
    background-color: #1E1E1E;
    color: #E0E0E0;
}

body.dark-mode .input-group {
    background: #2C2C2C;
}

body.dark-mode .input-group input {
    color: #E0E0E0;
}


body.dark-mode input:-webkit-autofill,
body.dark-mode input:-webkit-autofill:hover,
body.dark-mode input:-webkit-autofill:focus {
    -webkit-box-shadow: 0 0 0px 1000px #2C2C2C inset !important;
    -webkit-text-fill-color: #E0E0E0 !important;
    transition: background-color 5000s ease-in-out 0s;
}

body.dark-mode .fitness-text {
    color: #B0BEC5;
}

body.dark-mode .fitness-text-register {
    color: #E0E0E0;
}

body.dark-mode .flip-card-inner {
    box-shadow: 0px 4px 12px rgba(0, 0, 0, 0.6);
}
#darkModeToggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: transparent;
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    cursor: pointer;
    font-size: 20px;
    color: #2C2C2C;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background 0.3s ease, color 0.3s ease, transform 0.2s;
    z-index: 1000;
}

#darkModeToggle:hover {
    transform: scale(1.2);
}


body.dark-mode #darkModeToggle {
    color: #ffffff;      
}