@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,100..1000;1,9..40,100..1000&family=JetBrains+Mono:ital,wght@0,100..800;1,100..800&display=swap');

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

:root {
    --bg:       hsl(214, 25%, 11%);
    --surface:  hsl(214, 4%, 10%);
    --surface2: hsl(214, 4%, 14%);
    --border:   hsl(214, 5%, 19%);
    --border2:  hsl(214, 10%, 22%);
    --text:     hsl(215, 25%, 85%);
    --text2:    hsl(215, 25%, 85%);
    --text3:    hsl(216, 15%, 60%);
    --accent:   hsl(22, 100%, 62%);
    --accent2:  hsl(22, 100%, 78%);
    --danger:   hsl(0, 100%, 71%);
    --pass-a:   hsl(41, 100%, 47%);
    --pass-aa:  hsl(153, 39%, 49%);
    --pass-aaa: hsl(201, 64%, 53%);
    --mono:     'JetBrains Mono', 'Fira Code', monospace;
    --sans:     'DM Sans', system-ui, sans-serif;
    --radius:   0.625rem;     /* 10px */
    --radius-sm: 0.375rem;    /* 6px */
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--sans);
    min-height: 100vh;
    padding: 2rem 1rem;
    line-height: 1.6;
}

.app {
    max-width: 53.75rem;      /* 860px */
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 300;
    letter-spacing: -0.01em;
    line-height: 1.15;
    color: var(--text);
    font-family: var(--sans);
}

header h1 span {
    color: var(--accent);
    font-weight: 500;
}

header p {
    margin-top: 0.625rem;     /* 10px */
    color: var(--text3);
    font-family: var(--mono);
    font-size: 0.75rem;       /* 12px */
    letter-spacing: 0.07em;
    text-transform: uppercase;
}

.grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

@media (max-width: 40rem) {   /* 640px */
    .grid {
        grid-template-columns: 1fr;
    }
}

.panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
}

.panel-label {
    font-family: var(--mono);
    font-size: 0.6875rem;     /* 11px */
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text3);
    margin-bottom: 1rem;
}

.hex-row {
    display: flex;
    align-items: center;
    gap: 0.625rem;            /* 10px */
    margin-bottom: 1.125rem;  /* 18px ≈ 1.125rem */
}

.color-swatch {
    width: 2.375rem;          /* 38px */
    height: 2.375rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border2);
    flex-shrink: 0;
    cursor: pointer;
    transition: transform 0.15s;
    position: relative;
    overflow: hidden;
}

.color-swatch:hover {
    transform: scale(1.06);
}

.color-swatch input[type="color"] {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
    border: none;
    padding: 0;
}

.hex-input-wrap {
    flex: 1;
    position: relative;
}

.hex-input-wrap::before {
    content: '#';
    position: absolute;
    left: 0.625rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text3);
    font-family: var(--mono);
    font-size: 0.9rem;
    pointer-events: none;
}

.hex-input {
    width: 100%;
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.55rem 0.75rem 0.55rem 1.65rem;
    font-family: var(--mono);
    font-size: 0.9rem;
    color: var(--text);
    outline: none;
    transition: border-color 0.2s;
    text-transform: uppercase;
}

.hex-input:focus {
    border-color: var(--accent);
}

.hex-input.invalid {
    border-color: var(--danger);
}

.slider-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;             /* 12px */
}

.slider-row {
    display: flex;
    align-items: center;
    gap: 0.625rem;
}

.slider-label {
    font-family: var(--mono);
    font-size: 0.6875rem;
    color: var(--text3);
    width: 0.875rem;          /* 14px */
    text-align: center;
    flex-shrink: 0;
}

input[type="range"] {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 0.25rem;          /* 4px */
    border-radius: 0.125rem;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 0.9375rem;         /* 15px */
    height: 0.9375rem;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid var(--bg);
    cursor: pointer;
    transition: transform 0.1s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.slider-val {
    font-family: var(--mono);
    font-size: 0.6875rem;
    color: var(--text3);
    width: 2.125rem;          /* 34px */
    text-align: right;
    flex-shrink: 0;
}

/* Preview */
.preview-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    margin-bottom: 1rem;
}

.preview-label {
    font-family: var(--mono);
    font-size: 0.6875rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text3);
    margin-bottom: 1rem;
}

.preview-stage {
    border-radius: var(--radius-sm);
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1.125rem;            /* 18px */
    transition: background 0.2s;
    border: 1px solid var(--border);
}

.preview-large {
    font-size: 1.9rem;
    font-weight: 500;
    font-family: var(--sans);
    line-height: 1.2;
}

.preview-normal {
    font-size: 1rem;
    font-family: var(--sans);
    line-height: 1.65;
    font-weight: 300;
}

.preview-small {
    font-family: var(--mono);
    font-size: 0.8rem;        /* 12.8px ≈ 0.8rem */
    line-height: 1.55;
}

.preview-shape {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3.75rem;           /* 60px */
    height: 3.75rem;
    border-radius: 50%;
    font-family: var(--mono);
    font-size: 0.6875rem;
    font-weight: 500;
    letter-spacing: 0.04em;
}

/* CVD */
.cvd-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    margin-bottom: 1rem;
}

.cvd-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.125rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.cvd-title,
.cvd-reset {
    font-family: var(--mono);
    font-size: 0.6875rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text3);
}

.cvd-reset {
    background: none;
    border: 1px solid var(--border2);
    border-radius: var(--radius-sm);
    padding: 0.3125rem 0.75rem;   /* 5px 12px */
    cursor: pointer;
    color: var(--text3);
    transition: border-color 0.2s, color 0.2s;
}

.cvd-reset:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.cvd-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.625rem;                /* 10px */
}

@media (max-width: 32.5rem) {     /* 520px */
    .cvd-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.cvd-btn {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem 0.5rem;      /* 12px 8px */
    cursor: pointer;
    text-align: center;
    transition: border-color 0.2s, background 0.2s;
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
    align-items: center;
}

.cvd-btn:hover {
    border-color: var(--accent2);
    background: hsla(22, 100%, 62%, 0.05);
}

.cvd-btn.active {
    border-color: var(--accent);
    background: hsla(22, 100%, 62%, 0.08);
}

.cvd-name {
    font-family: var(--mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text2);
}

.cvd-sub {
    font-family: var(--mono);
    font-size: 0.625rem;      /* 10px */
    color: var(--text3);
    letter-spacing: 0.03em;
}

.cvd-swatch-pair {
    display: flex;
    gap: 0.1875rem;           /* 3px */
    margin-top: 0.375rem;
}

.cvd-dot {
    width: 0.6875rem;         /* 11px */
    height: 0.6875rem;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.1);
}

.cvd-active-label {
    font-family: var(--mono);
    font-size: 0.6875rem;
    color: var(--accent);
    text-align: center;
    margin-top: 0.75rem;
    min-height: 1rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

/* Results */
.results-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    margin-bottom: 1rem;
}

.ratio-display {
    text-align: center;
    margin-bottom: 1.5rem;
}

.ratio-number {
    font-size: clamp(2.8rem, 7vw, 4.5rem);
    font-weight: 300;
    font-family: var(--sans);
    line-height: 1;
    letter-spacing: -0.02em;
    transition: color 0.3s;
}

.ratio-unit {
    font-family: var(--mono);
    font-size: 0.6875rem;
    color: var(--text3);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-top: 0.3125rem;
}

.badges {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.625rem;
}

.badge {
    border-radius: var(--radius-sm);
    padding: 0.875rem 0.75rem;    /* 14px 12px */
    text-align: center;
    border: 1px solid transparent;
    transition: all 0.3s;
}

.badge-level {
    font-family: var(--mono);
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    margin-bottom: 0.25rem;
}

.badge-desc {
    font-size: 0.75rem;
    font-family: var(--mono);
    letter-spacing: 0.03em;
    opacity: 0.75;
}

.badge-req {
    font-size: 0.625rem;
    font-family: var(--mono);
    letter-spacing: 0.03em;
    margin-top: 0.375rem;
    opacity: 0.5;
}

.badge.fail {
    background: hsla(0, 100%, 71%, 0.06);
    border-color: hsla(0, 100%, 71%, 0.18);
    color: var(--danger);
    opacity: 0.6;
}

.badge-icon {
    font-size: 1.1rem;
    margin-bottom: 0.375rem;
}

.badge.pass .badge-icon::before,
.badge.pass-a .badge-icon::before,
.badge.pass-aa .badge-icon::before,
.badge.pass-aaa .badge-icon::before {
    content: '✓';
}

.badge.fail .badge-icon::before {
    content: '✗';
}

.badge.pass-a   { 
    border-color: hsla(41, 100%, 47%, 0.3);  
    background: hsla(41, 100%, 47%, 0.07);  
    color: var(--pass-a); 
}

.badge.pass-aa  { 
    border-color: hsla(153, 39%, 49%, 0.3); 
    background: hsla(153, 39%, 49%, 0.07); 
    color: var(--pass-aa); 
}

.badge.pass-aaa { 
    border-color: hsla(201, 64%, 53%, 0.3); 
    background: hsla(201, 64%, 53%, 0.07); 
    color: var(--pass-aaa); 
}

/* WAI */
.wai-info {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
}

.wai-info h3 {
    font-size: 0.6875rem;
    font-family: var(--mono);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text3);
    margin-bottom: 0.875rem;
}

.wai-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8125rem;     /* 13px */
}

.wai-table th {
    font-family: var(--mono);
    font-size: 0.6875rem;
    letter-spacing: 0.07em;
    text-transform: uppercase;
    color: var(--text3);
    text-align: left;
    padding: 0.375rem 0.5rem;
    border-bottom: 1px solid var(--border);
}

.wai-table td {
    padding: 0.5rem;
    color: var(--text2);
    border-bottom: 1px solid var(--border);
    font-family: var(--mono);
    font-size: 0.8125rem;
}

.wai-table tr:last-child td {
    border-bottom: none;
}

.wai-table td:first-child {
    font-weight: 500;
    color: var(--text);
}

.dot {
    width: 0.4375rem;         /* 7px */
    height: 0.4375rem;
    border-radius: 50%;
    display: inline-block;
    margin-right: 0.375rem;
    vertical-align: middle;
}

.dot-a   { background: var(--pass-a); }
.dot-aa  { background: var(--pass-aa); }
.dot-aaa { background: var(--pass-aaa); }