style.css

@import url('https://fonts.googleapis.com/css2?family=Dancing+Script:wght@500&display=swap');

html,
body {
    margin: 0;
    scroll-behavior: smooth;
}

@font-face {
    font-family: myFont;
    src: url(Roboto-Regular.ttf);
}

:root {
    --base: #f7f7f7;
    --base-light: #C7C7C7;
    --base-dark: #E0E0E0;
    --shadow: #C7C7C7;
    --letter: #eeebcc;
}

*::after,
*::before {
    content: "";
}

.envelope-container {
    display: flex;
    align-items: center;
    justify-content: center;
}

.content {
    position: relative;
    perspective: 600px;
}

.letter_shadow {
    position: absolute;
    width: 500px;
    height: 1px;
    background: transparent;
    border-radius: 30%;
    box-shadow: 50px 100px 10px 5px #eeeef3;
}

.letter {
    position: absolute;
    top: 10px;
    left: 10px;
    width: 580px;
    height: 340px;
    display: grid;
    grid-template-areas: 'headline'
        'options';
    align-items: center;
    justify-content: center;
    z-index: 15;
    border-radius: 2px;
    font-size: 50px;
    background: var(--letter);
    box-shadow: 0 1px 7px -2px var(--base);
    font-family: 'Dancing Script', cursive;
}

.letter .headline {
    grid-area: headline;
    text-align: center;
}

.letter .text {
    grid-area: text;
}

.title {
    display: flex;
    justify-content: center;
    text-align: center;
    font-family: myFont, serif;
    height: 20vh;
    align-items: center;
    font-size: 60px;
}

.sub-text {
    color: rgb(128, 128, 128);
    font-size: 5vh;
}

.envelope {
    position: relative;
    width: 600px;
    height: 360px;
    background: linear-gradient(#cccbd7 0.5px, var(--base-light) 0.5px);
    cursor: pointer;
}

.envelope::before {
    width: 600px;
    border-top: 230px solid #c0bfbf;
    border-left: 300px solid transparent;
    border-right: 300px solid transparent;
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    box-sizing: border-box;
    z-index: 30;
    transform-origin: top;
}

.envelope::after {
    content: "";
    position: absolute;
    top: 0;
    width: 600px;
    height: 360px;
    z-index: 25;
    background: linear-gradient(30deg, var(--base-dark) 47%, var(--shadow) 50%, var(--base) 50%) 300px 180px/300px 180px no-repeat,
    linear-gradient(31deg, var(--base) 49%, var(--shadow) 50%, transparent 50%) 0 0/304px 180px no-repeat,
    linear-gradient(150deg, var(--base) 50%, var(--shadow) 50%, var(--base-dark) 53%) 0 180px/302px 180px no-repeat,
    linear-gradient(148.7deg, transparent 50%, var(--shadow) 50%, var(--base) 51%) 300px 0/300px 180px no-repeat;
}

a {
    color: white;
    font-family: "Rubik", sans-serif;
    position: absolute;
    right: 20px;
    top: 20px;
    border: 2px solid white;
    text-decoration: none;
}

@media screen and (min-width: 451px) {
    a {
        font-size: 20px;
        padding: 8px 12px 8px 12px;
    }
}

@media screen and (max-width: 450px) {
    a {
        font-size: 16px;
        padding: 5px 8px 5px 8px;
    }
}

.options {
    grid-area: options;
    display: flex;
    flex-direction: column;
    gap: 10px;
    font-size: 15px;
}

.options button {
    background-color: transparent; /* Makes the background blend with the paper */
    border: none; /* Removes the solid border */
    padding: 10px 20px;
    cursor: pointer;
    color: black; /* Dark grey color, resembling ink */
    transition: all 0.3s ease;
    text-shadow: 1px 1px 1px rgba(0, 0, 0, 0.2); /* Slight shadow for depth */
}

.animated-inputs {
}

.animated-inputs .each {
    margin: 0 auto;
    padding: .2em 0;
    position: relative;
    text-align: left;
}

.animated-inputs label {
    display: inline-block;
    position: relative;
    line-height: 50px;
    padding: 0 0 0 80px;
    vertical-align: top;
    color: black;
    cursor: pointer;
    transition: color 0.3s ease;
}

.animated-inputs input[type="checkbox"],
.animated-inputs label::before {
    width: 20px;
    height: 20px;
    top: 50%;
    left: 0;
    margin-top: -25px;
    position: absolute;
    cursor: pointer;
    box-sizing: border-box;
}

.animated-inputs input[type="checkbox"] {
    opacity: 0;
    appearance: none;
    display: inline-block;
    vertical-align: middle;
    z-index: 100;
}

.animated-inputs label::before {
    content: '';
    border: 4px solid black;
    transition: opacity 0.3s ease;
}

.animated-inputs input[type="checkbox"]:checked + label {
    color: black;
}

.animated-inputs input[type="checkbox"]:checked + label::before {
    border: 4px solid black;
}

/* General SVG and path styles */
.animated-inputs svg {
    position: absolute;
    width: 40px;
    height: 40px;
    top: 50%;
    margin-top: -20px;
    left: 5px;
    pointer-events: none;
}

.animated-inputs svg path {
    stroke: black;
    stroke-width: 13px;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    transition: 0.8s stroke-dasharray ease, 0.8s stroke-dashoffset ease, 0.8s stroke ease;
}

/* Check */
.checkbox input[type="checkbox"] + label svg path {
    stroke-dasharray: 100px 200px;
    stroke-dashoffset: 101px;
    transition: 0.2s stroke-dasharray ease, 0.2s stroke-dashoffset ease, 0.2s stroke ease;
}

.checkbox input[type="checkbox"]:checked + label svg path {
    stroke-dashoffset: 0;
}

.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 100; /* Sit on top */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0, 0, 0); /* Fallback color */
    background-color: rgba(0, 0, 0, 0.4); /* Black w/ opacity */
}

.modal-content {
    display: flex;
    justify-content: center;
    background-color: #fefefe;
    margin: 15% auto; /* 15% from the top and centered */
    padding: 20px;
    border: 1px solid #888;
    width: 80%; /* Could be more or less, depending on screen size */
}

.arrow {
    height: 200px;
    transform: rotate(45deg);
}