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

body {
    font-family: "Poppins", sans-serif;
    font-weight: 400;
    color: #fff;
    font-size: 16px;
}

a {
    text-decoration: none;
    color: white;
}

img {
    max-width: 100%;
    height: auto;
}

.wrapper {
    background: linear-gradient(180deg, rgba(0,0,0,1) 0%, rgba(26,14,1,1) 100%);
    width: 100%;
    min-height: 100vh;
}

.container {
    width: 90%;
    max-width: 1400px;
    margin: 0 auto;
}

header {
    padding: 50px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header .logo {
    text-transform: uppercase;
    font-size: 29px;
    font-weight: 800;
}

header nav {
    width: auto;
}

header nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
    align-items: center;
    position: relative;
    z-index: 2;
}

header nav ul li {
    position: relative;
}

header nav ul li a {
    color: #fff;
}

header nav ul li.active::after {
    content: '';
    display: block;
    width: 40px;
    height: 5px;
    background: #DC7000;
    border-radius: 10px;
    margin-top: 8px;
}

header nav ul li:not(.active):not(.btn) a:hover {
    border-bottom: 3px solid #DC7000;
    padding-bottom: 3px;
}

header nav ul li.btn a {
    background: #FA9021;
    padding: 9px 17px;
    border-radius: 5px;
    transition: 0.3s;
}

header nav ul li.btn a:hover {
    background: #3b2003;
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: #1f1f1f;
    min-width: 220px;
    padding: 10px 0;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    z-index: 1000;
}

.dropdown-menu li a {
    display: block;
    padding: 12px 20px;
    color: #aaa;
    font-size: 16px;
    transition: 0.3s;
}

.dropdown-menu li a:hover {
    background: #2a2a2a;
    color: #fff;
    padding-left: 25px;
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown > a {
    transition: 0.3s;
}

.dropdown:hover > a {
    color: #FA8305;
}

.calculator-section {
    display: flex;
    justify-content: center;
    padding: 40px 0 100px;
}

.calculator {
    width: 380px;
    max-width: 100%;
    background: rgba(255,255,255,0.03);
    border: 2px solid rgba(255,255,255,0.15);
    border-radius: 25px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.calculator h1 {
    text-align: center;
    margin-bottom: 20px;
    font-size: 32px;
}

#display {
    width: 100%;
    height: 75px;
    border: none;
    outline: none;
    border-radius: 15px;
    margin-bottom: 20px;
    padding: 15px;
    font-size: 30px;
    text-align: right;
    background: #111;
    color: white;
    overflow-x: auto;
    white-space: nowrap;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.buttons button {
    height: 65px;
    border: none;
    border-radius: 15px;
    font-size: 22px;
    background: #1b1b1b;
    color: white;
    cursor: pointer;
    transition: 0.3s ease;
}

.buttons button:hover {
    background: #DC7000;
    transform: scale(1.05);
}

.buttons .zero {
    grid-column: span 2;
}

.buttons .equal {
    background: #FA9021;
    color: white;
}

.buttons .equal:hover {
    background: #DC7000;
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 20px;
    }

    header nav {
        width: 100%;
    }

    header nav ul {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .dropdown-menu {
        position: static;
        display: block;
        background: transparent;
        box-shadow: none;
        padding: 5px 0 0 12px;
        min-width: auto;
    }

    .dropdown-menu li a {
        padding: 6px 0;
        color: #ccc;
    }

    .dropdown-menu li a:hover {
        background: transparent;
        color: #FA8305;
        padding-left: 0;
    }

    .calculator-section {
        padding: 30px 0 50px;
    }

    .calculator {
        width: 100%;
        max-width: 360px;
        padding: 20px;
    }

    .calculator h1 {
        font-size: 26px;
    }

    #display {
        height: 65px;
        font-size: 24px;
        padding: 12px;
    }

    .buttons {
        gap: 10px;
    }

    .buttons button {
        height: 55px;
        font-size: 20px;
    }
}