@font-face {
    font-family: "Neulis Neue";
    src: url(../fonts/NeulisNeue_medium.otf) format("opentype");
    font-weight: 400;
    font-style: normal;
}

@font-face {
    font-family: "Neulis Neue";
    src: url(../fonts/NeulisNeue_bold.otf) format("opentype");
    font-weight: 700;
    font-style: normal;
}

@font-face {
    font-family: "Neulis Neue";
    src: url(../fonts/NeulisNeue_black.otf) format("opentype");
    font-weight: 900;
    font-style: normal;
}

:root {
    --font-stack-heading: "Neulis Neue", Helvetica, Arial, sans-serif;
    --font-stack-body: Helvetica, Arial, sans-serif;
    --font-weight-heading: 900;
    --font-weight-body: 400;

    --scale-ratio: 1.618;
    --font-size-base: 1.6rem;
    --font-size-sm: 0.875rem;
    --font-size-md: var(--font-size-base);
    --font-size-lg: calc(var(--font-size-base) * var(--scale-ratio));
    --font-size-xl: calc(var(--font-size-lg) * var(--scale-ratio));

    --slate: #3a3a3a;
    --grey: #696969;
    --leaf: #00a366;
    --jade: #93c8b5;
    --jade-200: #d5e4df;
}

*, *::before, *::after {
    box-sizing: border-box;
}

html {
    font-size: 62.5%;
    line-height: 1.5;
    -ms-text-size-adjust: 100%;
    -webkit-text-size-adjust: 100%;
}

body {
    font-size: 1.6rem;
    line-height: 1.2;
    font-family: var(--font-stack-body);
    font-weight: var(--font-weight-body);
    font-size: var(--font-size-md);
    padding: 0;
    margin: 0;
}

h1, h2, h3, h4, h5 {
    font-family: var(--font-stack-heading);
    font-weight: var(--font-weight-heading);
}

a {
    color: var(--leaf);
}

body {
    display: flex;
    flex-flow: column nowrap;
    min-height: 100vh;
}

header {
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    padding-block: 3.6rem 2.8rem;
}

header img {
    max-width: 268px;
}

header nav {
    margin-block-start: 2.4rem;
}

header nav ul {
    list-style: none;
    display: flex;
    flex-flow: row wrap;
    column-gap: 1.6rem;
}

header nav ul li a {
    font-family: var(--font-stack-heading);
    font-weight: var(--font-weight-heading);
    font-size: 1.9rem;
    text-decoration: none;
}

header nav ul li a:hover {
    text-decoration: wavy underline;
    text-decoration-skip-ink: none;
    text-underline-offset: 3px;
    text-decoration-color: var(--jade);
}

main {
    flex-grow: 1;
    background: var(--jade-200);
}

.hero {
    max-width: 1000px;
    margin-inline: auto;
    padding-block: 6.8rem 5.6rem;
}

.hero h2 {
    color: var(--slate);
    font-size: var(--font-size-xl);
    text-wrap: balance;
    margin-block-end: 1.6rem;
}

.hero p {
    font-size: var(--font-size-lg);
    color: var(--slate);
}

.hero .hero-green {
    color: var(--leaf);
    font-family: var(--font-stack-heading);
    font-weight: var(--font-weight-heading);
}

.demo {
    margin-inline: auto;
    display: flex;
    justify-content: center;
}

.demo a {
    font-size: 2rem;
    font-weight: bold;
    color: white;
    text-decoration: none;
    background: var(--leaf);
    padding: 1.8rem 2.4rem;
    border-radius: 3.6rem;
}

.cards {
    margin-inline: auto;
    display: flex;
    flex-flow: row wrap;
    justify-content: center;
    column-gap: 2.4rem;
    margin-block-start: 4.8rem;
}

.cards .card {
    max-width: 280px;
    background: white;
    border-radius: 1rem;
    padding: 1.2rem;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.cards .card i {
    display: block;
    font-size: 3.6rem;
    color: var(--leaf);
}

.cards .card:nth-child(2) i {
    color: #cac35a;
}

.cards .card:nth-child(3) i {
    color: #79a5c9;
}

.cards .card h2 {
    font-size: 2.2rem;
    font-weight: var(--font-weight-heading);
    font-family: var(--font-stack-heading);
    margin-block: 2rem 1rem;
    color: var(--slate);
}

.cards .card p {
    color: var(--grey);
}