<div class="container">
        <div class="navbar">
            <div class="menu">
                <h3 class="logo">Coding<span>Beast</span></h3>
                <div class="hamburger-menu">
                    <div class="bar"></div>
                </div>
            </div>
        </div>
        <div class="main-container">
            <div class="main">
                <header>
                    <div class="overlay">
                        <h2 class="title">Future is here</h2>
                        <p class="description">“All our dreams can come true,
                            if we have the courage to pursue them.” 
                        </p>
                        <a href="#" class="btn">Read More</a>
                    </div>
                </header>
            </div>
            <div class="shadow one"></div>
            <div class="shadow two"></div>
        </div>
        <div class="links">
            <ul>
                <li class="active">
                    <a href="#" style="--i: 0.05s">Home</a>
                </li>
                <li>
                    <a href="#" style="--i: 0.1s">About</a>
                </li>
                <li>
                    <a href="#" style="--i: 0.15s">Contact</a>
                </li>
                <li>
                    <a href="#" style="--i: 0.2s">Service</a>
                </li>
                <li>
                    <a href="#" style="--i: 0.25s">Portfolio</a>
                </li>
            </ul>
        </div>
    </div>

@import url('https://fonts.googleapis.com/css2?family=Recursive:wght@400;500;600;700;800;900&display=swap');

*{ padding:0; margin: 0; box-sizing: border-box; }

body{ font-family: 'Recursive', sans-serif; overflow: hidden; }

.container{ max-height: 100vh; width: 100%; background-color: #131414;
    background-image: linear-gradient(135deg, #131414 0%, #000000
    100%); transform-style: preserve-3d; overflow: hidden;
}

.navbar{ position: fixed; top: 0; left: 0; width: 100%; z-index: 10;
    height: 5rem;
}

.menu{ max-width: 72rem; width: 100%; height: 100%; margin: 0 auto;
    padding: 0 2rem; display: flex; justify-content: space-between;
    align-items: center; color: #fff;
}

.logo{
    font-size: 1.8rem; font-weight: 600; text-transform: uppercase;
    letter-spacing: 2px; line-height: 4rem; margin-top: 20px;
}

.logo span{ font-size: 1.8rem; margin-left: 5px; color: #e20f2f; }

.hamburger-menu{ height: 4rem; width: 3rem; cursor: pointer;
    display: flex; align-items: center; justify-content: flex-end; }

.bar{ width: 1.9rem; height: 1.5px; border-radius: 2px;
    background-color: #eee; transition: 0.5s; position: relative; }

.bar::before, .bar::after{ content: ""; position: absolute;
    width: inherit; height: inherit; background-color: #eee;
    transition: 0.5s; }

.bar::before{ transform: translateY(-9px); }

.bar::after{ transform: translateY(9px); }

.main-container{ overflow: hidden; }

.main{ position: relative; width: 100%; left: 0; z-index: 5;
    overflow: hidden; transform-origin: left; 
    transform-style: preserve-3d; transition: 0.5s;
}

header{ min-height: 100vh; width: 100%;
    background: url("https://i.postimg.cc/0Q09GwLQ/image.jpg") no-repeat top center / cover;
    position: relative;
}

.overlay{ position: absolute; width: 100%; height: 100%; top: 0;
    left: 0; background-color: rgba(0, 0, 0, 0.712);
    display: flex; justify-content: center; align-items: center;
    flex-direction: column; color: #fff;
}

.inner{ max-width: 35rem; text-align: center; color: #fff;
    padding: 0 2rem;
}

.title{ font-size: 3rem; }

.description{ margin: 10px 0; text-align: center; width: 50%;
    font-size: 1.5rem;
}

.btn{ margin-top: 1rem; padding: 0.6rem 1.8rem;
    background-color: #e20f2f; border: none; border-radius: 25px;
    color: #fff; text-transform: uppercase; cursor: pointer;
    text-decoration: none;
}

.container.active .bar{ transform: rotate(360deg);
    background-color: transparent;
}

.container.active .bar::before{ 
    transform: translateY(0) rotate(45deg);
}

.container.active .bar::after{
    transform: translateY(0) rotate(-45deg);
}

.container.active .main{
    animation: main-animation 0.5s ease; cursor: pointer;
    transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                translateZ(310px) scale(0.5);
}

@keyframes main-animation{
    from{ transform: translate(0); }
    to{
        transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                    translateZ(310px) scale(0.5);
    }
}

.links{ position: absolute; width: 30%; right: 0; top: 0; 
    height: 100vh; z-index: 2; overflow: hidden;
    display: flex; justify-content: flex-start; align-items: center;
    margin-left: 10px;
}

ul{ list-style: none; }

ul li.active a{ color: #e20f2f; }

.links a{ text-decoration: none; color: #eee; padding: 0.7rem 0;
    display: inline-block; font-size: 1.8rem; font-weight: 300;
    text-transform: uppercase; letter-spacing: 1px; transition: 0.3s;
    opacity: 0; transform: translateY(10px);
    animation: hide 0.5s forwards ease;
}

.links a:hover{ color: #e20f2f; }

.container.active .links a{ 
    animation: appear 0.5s forwards ease var(--i);
}

@keyframes appear{
    from { opacity: 0; transform: translateY(10px); }
    to{ opacity: 1; transform: translateY(0px); }
}

@keyframes hide{
    from { opacity: 1; transform: translateY(0px); }
    to{ opacity: 0; transform: translateY(10px); }
}

.shadow{ position: absolute; width: 100%; height: 100vh; top: 0;
    left: 0; transform-style: preserve-3d; transform-origin:left;
    transition: 0.5s; background-color: #fff; }

.shadow.one{ z-index: -1; opacity: 0.15; }

.shadow.two{ z-index: -2; opacity: 0.1; }

.container.active .shadow.one{
    animation: shadow-one 0.6s ease-out;
    transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                translateZ(215px) scale(0.5);
}

@keyframes shadow-one{
    0%{
        transform: translate(0);
    }
    5%{
        transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                    translateZ(310px) scale(0.5);
    }
    100%{
        transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                    translateZ(215px) scale(0.5);
    }
}

.container.active .shadow.two{
    animation: shadow-two 0.6s ease-out;
    transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                translateZ(120px) scale(0.5);
}

@keyframes shadow-two{
    0%{
        transform: translate(0);
    }
    20%{
        transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                    translateZ(310px) scale(0.5);
    }
    100%{
        transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                    translateZ(120px) scale(0.5);
    }
}

.container.active .main:hover + .shadow.one{
    transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                translateZ(230px) scale(0.5);
}
.container.active .main:hover{
    transform: perspective(1300px) rotateY(20deg) translateY(10px) 
                translateZ(340px) scale(0.5);
}

const hamburger_menu = document.querySelector(".hamburger-menu");

const container = document.querySelector(".container");

hamburger_menu.addEventListener("click", () => {
    container.classList.toggle("active");
})