/*
 * Color Contrast Checker
 * Author: Thomas Brown
 * Website: https://thomasbrown.app
 */

:root {
    color-scheme: light;
    font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-synthesis: none;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    --ink: #19352a;
    --muted: #52675c;
    --paper: #f6f8f4;
    --line: #d9e3d8;
    --green: #285c42;
    --focus: #bc571d;
}

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

html {
    scroll-behavior: smooth;
}

body {
    min-width: 0;
    margin: 0;
    background: #edf2eb;
    color: var(--ink);
    line-height: 1.5;
}

button,
input {
    font: inherit;
}

button {
    cursor: pointer;
}

a {
    color: inherit;
}

:focus-visible {
    outline: 3px solid var(--focus);
    outline-offset: 3px;
}

[hidden] {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.container {
    width: min(100% - 48px, 1160px);
    margin-inline: auto;
}

.skip-link {
    position: fixed;
    z-index: 20;
    top: 12px;
    left: 12px;
    transform: translateY(-160%);
    padding: 10px 16px;
    border-radius: 8px;
    background: #fff;
    color: #173b2b;
    font-weight: 700;
    box-shadow: 0 4px 18px #102c2340;
}

.skip-link:focus {
    transform: translateY(0);
}

.site-header {
    background: #193a2d;
    color: #fff;
}

.header-inner,
.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.header-inner {
    min-height: 76px;
}

.site-name {
    font-size: 1.05rem;
    font-weight: 800;
    letter-spacing: -.02em;
}

.site-header a {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    border-bottom: 1px solid #c9e2cf;
    color: #f1fff4;
    font-size: .91rem;
    font-weight: 700;
    text-decoration: none;
}

.site-header a:hover {
    color: #d5f0db;
}

.site-header a:focus-visible {
    outline-color: #ffd681;
}

main {
    padding-block: 54px 80px;
}

.intro {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    overflow: hidden;
    margin-bottom: 28px;
    padding: clamp(30px, 5vw, 58px);
    border: 1px solid #b9d1bf;
    border-radius: 24px;
    background: radial-gradient(circle at 84% 28%, #d0e8d1 0, transparent 31%), linear-gradient(125deg, #f9fbf5, #e5f0e6);
}

.intro > div:first-child {
    position: relative;
    z-index: 1;
    max-width: 690px;
}

.eyebrow {
    margin: 0 0 12px;
    color: #315f43;
    font-size: .72rem;
    font-weight: 800;
    letter-spacing: .13em;
    text-transform: uppercase;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1,
h2,
h3 {
    line-height: 1.15;
    letter-spacing: -.035em;
}

h1 {
    max-width: 630px;
    margin-bottom: 17px;
    font-size: clamp(2.4rem, 5vw, 4.1rem);
}

.lead {
    max-width: 600px;
    margin-bottom: 0;
    color: #405c4c;
    font-size: clamp(1rem, 1.6vw, 1.17rem);
    line-height: 1.65;
}

.intro-mark {
    position: relative;
    flex: 0 0 218px;
    height: 198px;
}

.intro-mark span {
    position: absolute;
    display: grid;
    place-items: center;
    width: 151px;
    height: 151px;
    border-radius: 28px;
    font-size: 4rem;
    font-weight: 800;
    letter-spacing: -.09em;
    box-shadow: 0 12px 28px #183b2a21;
}

.intro-mark span:first-child {
    top: 0;
    right: 0;
    transform: rotate(11deg);
    background: #254d37;
    color: #fff;
}

.intro-mark span:last-child {
    bottom: 0;
    left: 0;
    transform: rotate(-11deg);
    border: 1px solid #a9c6ac;
    background: #f9fcf5;
    color: #254d37;
}

.tool-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    gap: 24px;
}

.panel {
    min-width: 0;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: 0 12px 30px #173a2509;
}

.controls-panel,
.results-panel {
    padding: clamp(23px, 3vw, 36px);
}

.panel-heading {
    margin-bottom: 28px;
    padding-bottom: 24px;
    border-bottom: 1px solid #e5ebe2;
}

h2 {
    margin-bottom: 10px;
    font-size: clamp(1.7rem, 2.5vw, 2.1rem);
}

.panel-heading > p:last-child,
.preview-heading > p {
    margin-bottom: 0;
    color: var(--muted);
    font-size: .94rem;
}

.color-group h3,
.presets h3 {
    margin-bottom: 13px;
    font-size: 1rem;
    letter-spacing: -.015em;
}

.color-row {
    display: grid;
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 12px;
}

.picker-field,
.hex-field {
    min-width: 0;
}

.picker-field label,
.hex-field label {
    display: block;
    margin-bottom: 7px;
    color: #43584a;
    font-size: .78rem;
    font-weight: 700;
}

.picker-field input,
.hex-field input {
    display: block;
    width: 100%;
    height: 48px;
    border: 1px solid #aebfaf;
    border-radius: 9px;
    background: #fff;
}

.picker-field input {
    padding: 4px;
    cursor: pointer;
}

.picker-field input::-webkit-color-swatch-wrapper {
    padding: 0;
}

.picker-field input::-webkit-color-swatch {
    border: none;
    border-radius: 5px;
}

.picker-field input::-moz-color-swatch {
    border: none;
    border-radius: 5px;
}

.hex-field input {
    padding: 0 14px;
    color: var(--ink);
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: .055em;
}

.hex-field input[aria-invalid="true"] {
    border: 2px solid #a03225;
    background: #fff8f6;
}

.field-help,
.field-error {
    margin: 9px 0 0;
    font-size: .79rem;
    line-height: 1.45;
}

.field-help {
    color: #53685b;
}

.field-error {
    color: #8c291e;
    font-weight: 700;
}

.no-script {
    margin: 0 0 22px;
    padding: 12px 14px;
    border: 1px solid #e8bea8;
    border-radius: 9px;
    background: #fff1e9;
    color: #823719;
    font-size: .88rem;
    font-weight: 700;
}

.swap-button {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin: 20px 0;
    padding: 9px 14px;
    border: 1px solid #a2baa7;
    border-radius: 999px;
    background: #f0f6ef;
    color: #1f4932;
    font-size: .86rem;
    font-weight: 800;
    transition: background-color .18s ease, transform .18s ease;
}

.swap-button:hover {
    transform: translateY(-1px);
    background: #e0eee0;
}

.swap-button span {
    font-size: 1.15em;
    line-height: 1;
}

.presets {
    margin-top: 27px;
    padding-top: 23px;
    border-top: 1px solid #e5ebe2;
}

.preset-list {
    display: flex;
    flex-wrap: wrap;
    gap: 9px;
}

.preset-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-height: 42px;
    padding: 5px 11px 5px 6px;
    border: 1px solid #bbcebd;
    border-radius: 999px;
    background: #fff;
    color: #213c2b;
    font-size: .79rem;
    font-weight: 800;
    transition: border-color .18s ease, background-color .18s ease;
}

.preset-button:hover {
    border-color: #558064;
    background: #f0f6ee;
}

.preset-swatch {
    position: relative;
    display: block;
    flex: none;
    width: 27px;
    height: 27px;
    overflow: hidden;
    border: 1px solid #829989;
    border-radius: 50%;
    background: var(--preset-background);
}

.preset-swatch::after {
    position: absolute;
    top: 7px;
    left: 7px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--preset-foreground);
    content: "";
}

.ratio-block {
    margin-bottom: 22px;
    padding: 25px;
    border: 1px solid #bad4bd;
    border-radius: 15px;
    background: linear-gradient(135deg, #e7f3e7, #f4f9f0);
}

.ratio-block > p:first-child {
    margin-bottom: 5px;
    color: #315941;
    font-size: .83rem;
    font-weight: 800;
}

.ratio-number {
    display: flex;
    align-items: baseline;
    min-height: 78px;
    color: #193a2b;
    font-size: clamp(3.2rem, 6vw, 4.8rem);
    font-weight: 850;
    letter-spacing: -.075em;
    line-height: 1.1;
}

.ratio-number span {
    margin-left: 2px;
    font-size: .44em;
    letter-spacing: -.03em;
}

#ratio-caption {
    margin-bottom: 0;
    color: #365947;
    font-size: .9rem;
    font-weight: 700;
}

.criteria {
    display: grid;
    gap: 9px;
}

.criterion {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    min-height: 64px;
    padding: 11px 14px;
    border: 1px solid #dce6da;
    border-radius: 10px;
    background: #f8faf7;
}

.criterion strong,
.criterion span {
    display: block;
}

.criterion strong {
    color: #243d2c;
    font-size: .88rem;
    line-height: 1.25;
}

.criterion span {
    margin-top: 3px;
    color: #53685a;
    font-size: .74rem;
}

.criterion b {
    flex: none;
    min-width: 61px;
    padding: 5px 8px;
    border-radius: 6px;
    background: #e6ebe4;
    color: #3c5141;
    font-size: .75rem;
    text-align: center;
}

.criterion.passes {
    border-color: #a6d4b1;
    background: #edf8ef;
}

.criterion.passes b {
    background: #cfead5;
    color: #165432;
}

.criterion.fails {
    border-color: #edc1b8;
    background: #fff3f0;
}

.criterion.fails b {
    background: #f8dcd4;
    color: #8b2e20;
}

.result-note {
    margin: 19px 0 0;
    color: #52675b;
    font-size: .8rem;
    line-height: 1.55;
}

.preview-panel {
    margin-top: 24px;
    overflow: hidden;
}

.preview-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 24px;
    padding: 30px clamp(23px, 3vw, 36px);
}

.preview-heading h2 {
    margin-bottom: 0;
}

.preview-heading > p {
    max-width: 290px;
    text-align: right;
}

.preview-surface {
    min-height: 290px;
    padding: clamp(28px, 5vw, 52px);
    background: var(--preview-background, #f6f8f4);
    color: var(--preview-foreground, #19352a);
    overflow-wrap: anywhere;
}

.preview-label {
    margin-bottom: 9px;
    font-size: .75rem;
    font-weight: 800;
    letter-spacing: .09em;
    text-transform: uppercase;
}

.preview-surface h3 {
    max-width: 720px;
    margin-bottom: 28px;
    font-size: 24px;
}

.preview-body {
    max-width: 670px;
    margin-bottom: 26px;
    font-size: 1rem;
    line-height: 1.65;
}

.preview-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.sample-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 43px;
    padding: 10px 16px;
    border: 2px solid var(--preview-foreground, #19352a);
    border-radius: 8px;
    font-size: .88rem;
    font-weight: 750;
    line-height: 1.2;
}

.sample-button-filled {
    background: var(--preview-foreground, #19352a);
    color: var(--preview-background, #f6f8f4);
}

.sample-button-outline {
    background: transparent;
    color: var(--preview-foreground, #19352a);
}

.site-footer {
    border-top: 1px solid #cbdbcc;
    background: #e5ede4;
    color: #3f5949;
    font-size: .83rem;
}

.footer-inner {
    min-height: 76px;
}

@media (max-width: 900px) {
    .intro-mark {
        flex-basis: 170px;
        height: 160px;
    }

    .intro-mark span {
        width: 120px;
        height: 120px;
        border-radius: 24px;
        font-size: 3.1rem;
    }

    .tool-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 620px) {
    .container {
        width: min(100% - 28px, 1160px);
    }

    .header-inner {
        min-height: 66px;
    }

    main {
        padding-block: 24px 50px;
    }

    .intro {
        padding: 29px 24px;
    }

    .intro-mark {
        display: none;
    }

    .tool-grid {
        gap: 16px;
    }

    .panel {
        border-radius: 16px;
    }

    .controls-panel,
    .results-panel {
        padding: 24px 20px;
    }

    .preview-panel {
        margin-top: 16px;
    }

    .preview-heading {
        display: block;
        padding: 25px 20px;
    }

    .preview-heading > p {
        max-width: none;
        margin-top: 10px;
        text-align: left;
    }

    .preview-surface {
        padding: 28px 22px;
    }
}

@media (max-width: 390px) {
    .site-name {
        font-size: .92rem;
    }

    .site-header a {
        font-size: .8rem;
    }

    .color-row {
        grid-template-columns: 92px minmax(0, 1fr);
    }

    .criterion {
        padding-inline: 10px;
    }

    .criterion b {
        min-width: 52px;
    }

    .footer-inner {
        flex-wrap: wrap;
        justify-content: center;
        gap: 2px 14px;
        padding-block: 18px;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: .01ms !important;
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
    }
}