:root {
    /* --clr-accent-400: ; */
    /* --clr-accent-100 ; */

    --clr-primary-400: black;

    /* --clr-neutral-100: ; */
    /* --clr-neutral-900: ; */

    --clr-background: #FFFFFF;
    --clr-surface: #FFFFFF;
    --clr-error: #B00020;

    --clr-gray-50: #FAFAFA;
    --clr-gray-100: #F5F5F5;
    --clr-gray-200: #EEEEEE;
    --clr-gray-300: #E0E0E0;
    --clr-gray-400: #BDBDBD;
    --clr-gray-500: #9E9E9E;
    --clr-gray-600: #757575;
    --clr-gray-700: #616161;
    --clr-gray-800: #424242;
    --clr-gray-900: #212121;


    --ff-primary: 'Noto Sans KR', sans-serif;

    --ff-body: var(--ff-primary);

    --fw-light: 100;
    --fw-regular: 300;
    --fw-semi-bold: 400;
    --fw-bold: 500;

    /* 1rem: 16px (default) */
    --fs-100: .6875rem;
    --fs-200: .75rem;
    --fs-300: .8125rem;
    --fs-400: .875rem;
    --fs-500: .9375rem;
    --fs-600: 1rem;
    --fs-700: 1.5rem;
    --fs-800: 2.5rem;
    --fs-900: 3.5rem;

    --fs-body: var(--fs-400);
    --fs-small: var(--fs-200);
    --fs-regular: var(--fs-400);
    --fs-large: var(--fs-500);
    --fs-secondary-heading: var(--fs-600);
    --fs-primary-heading: var(--fs-700);
    --fs-nav: var(--fs-500);
    --fs-button: var(--fs-300);

    @media (min-width: 768px) {
        :root {
            --fs-body: var(--fs-300);
            --fs-small: var(--fs-100);
            --fs-regular: var(--fs-300);
            --fs-large: var(--fs-400);
            --fs-secondary-heading: var(--fs-500);
            --fs-primary-heading: var(--fs-600);

            --fs-nav: var(--fs-400);
        }
    }
}



/* https://piccalil.li/blog/a-modern-css-reset */

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

/* Remove default margin */
* {
    margin: 0;
    padding: 0;
    font: inherit;
}

/* Remove list styles on ul, ol elements with a list role, which suggests default styling will be removed */
ul[role='list'],
ol[role='list'] {
  list-style: none;
}

/* Set core root defaults */
html:focus-within {
  scroll-behavior: smooth;
}

html,
body {
    height: 100%;
}

/* Set core body defaults */
body {
    line-height: 1.5;
    font-family: var(--ff-body);
    color: var(--clr-primary-400);
}

/* A elements that don't have a class get default styles */
a:not([class]) {
    text-decoration-skip-ink: auto;
}

/* Make images easier to work with */
img,
picture,
svg {
    max-width: 100%;
    display: block;
}

/* Remove all animations, transitions and smooth scroll for people that prefer not to see them */
@media (prefers-reduced-motion: reduce) {
  html:focus-within {
   scroll-behavior: auto;
  }
  
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Utility classes */

.text-primary {
    color: var(--clr-primary-400);
}
.text-error {
    color: var(--clr-error);
}
.text-secondary {
    color: var(--clr-gray-600);
}

.bg-primary {
    color: var(--clr-background);
}


.fw-bold {
    font-weight: var(--fw-bold);
}
.fw-semi-bold {
    font-weight: var(--fw-semi-bold);
}
.fw-regular {
    font-weight: var(--fw-regular);
}

.fs-primary-heading {
    font-size: var(--fs-primary-heading);
}
.fs-secondary-heading {
    font-size: var(--fs-secondary-heading);
}
.fs-small {
    font-size: var(--fs-small);
}
.fs-regular {
    font-size: var(--fs-regular);
}
.fs-large {
    font-size: var(--fs-large);
}
.fs-nav {
    font-size: var(--fs-nav);
}
.fs-button {
    font-size: var(--fs-button);
}

.fs-300 { font-size: var(--fs-300) }
.fs-400 { font-size: var(--fs-400) }
.fs-500 { font-size: var(--fs-500) }
.fs-600 { font-size: var(--fs-600) }



.d-none { display: none; }
.d-block  { display: block; }
.d-flex { display: flex; }

@media (min-width: 768px) {
    .d-sm-none { display: none; }
    .d-sm-block { display: block; }
    .d-sm-flex { display: flex; }
}


/* general styling */
body {
    font-size: var(--fs-body);
    font-family: var(--ff-body);
    color: var(--clr-gray-900);
    font-weight: var(--fw-regular);
}

.container {
    --max-width: 1170px;
    --padding: 1rem;

    width: min(var(--max-width), 100% - (var(--padding) * 2));
    margin-left: auto;
    margin-right: auto;
}

.even-columns {
    display: grid;
    gap: 1rem;
}

@media (min-width: 50em) {
    .even-columns {
        grid-auto-flow: column;
        grid-auto-columns: 1fr;
    }
}

button {
    background-color: black; /* Green */
    border: none;
    color: white;
    padding: 8px 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--fs-button);
    transition-duration: 0.2s;
    cursor: pointer;
}
button:hover {
    background-color: var(--clr-gray-800);
}

button[inverted] {
    background-color: white;
    color: black;
    border: 1px solid black;
}