@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap');

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(270deg,
        #0d0d0d, #1a1a1a, #262626, #333333, #404040, #4d4d4d,
        #595959, #666666, #737373, #808080, #8c8c8c, #999999
    );
    background-size: 2400% 2400%;
    animation: gradientBG 30s ease infinite;
    color: #fff;
    padding: 20px;
}

@keyframes gradientBG {
    0% {background-position: 0% 50%;}
    50% {background-position: 100% 50%;}
    100% {background-position: 0% 50%;}
}

.container {
    text-align: center;
    background: rgba(15, 15, 15, 0.9);
    padding: 60px 80px;
    border-radius: 25px;
    box-shadow: 0 0 40px rgba(0,255,204,0.2);
    transition: transform 0.3s;
    max-width: 90%;
}

.container:hover {
    transform: scale(1.03);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 25px;
    color: #00ffcc;
    text-shadow: 0 0 10px #00ffcc, 0 0 20px #00ffcc;
}

#value {
    font-size: 4rem;
    margin: 30px 0;
    color: #ff00ff;
    text-shadow: 0 0 20px #ff00ff, 0 0 40px #ff00ff;
    transition: all 0.3s;
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    0% { text-shadow: 0 0 10px #ff00ff, 0 0 20px #ff00ff; }
    100% { text-shadow: 0 0 30px #ff00ff, 0 0 60px #ff00ff; }
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 25px;
    flex-wrap: wrap;
}

.btn {
    background: linear-gradient(45deg, 
        #1c1c1c, #2a2a2a, #383838, #464646, #555555, #636363,
        #717171, #7f7f7f, #8d8d8d, #9b9b9b, #a9a9a9, #b7b7b7
    );
    background-size: 2400% 2400%;
    color: #00ffcc;
    border: none;
    padding: 35px 45px;
    font-size: 2.5rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 10px 25px rgba(0,255,204,0.3);
    animation: btnGradient 15s ease infinite;
    flex: 1 1 100px;
    max-width: 150px;
}

.btn:hover {
    transform: translateY(-7px) scale(1.1);
    box-shadow: 0 15px 35px rgba(0,255,204,0.6);
}

.reset {
    color: #ff3c3c;
    box-shadow: 0 10px 25px rgba(255,60,60,0.3);
}

.reset:hover {
    box-shadow: 0 15px 35px rgba(255,60,60,0.6);
}

@keyframes btnGradient {
    0% {background-position: 0% 50%;}
    50% {background-position: 100% 50%;}
    100% {background-position: 0% 50%;}
}

/* Responsive Media Queries */
@media (max-width: 768px) {
    .container {
        padding: 40px 50px;
    }
    h1 {
        font-size: 2rem;
    }
    #value {
        font-size: 3rem;
    }
    .btn {
        padding: 20px 35px;
        font-size: 2rem;
        max-width: 120px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 30px 20px;
    }
    h1 {
        font-size: 1.5rem;
    }
    #value {
        font-size: 2.5rem;
    }
    .buttons {
        flex-direction: column; /* stack vertically */
        gap: 20px;
    }
    .btn {
        padding: 15px 25px;
        font-size: 1.8rem;
        max-width: 100%;
    }
}