:root {
    /* KoalaSync nature system: forest neutrals, eucalyptus brand, warm supporting accents. */
    --bg-base: oklch(0.23 0.028 155);
    --surface: oklch(0.30 0.035 150);
    --surface-deep: oklch(0.205 0.025 155);
    --surface-alt: oklch(0.265 0.032 150);
    --border-soft: oklch(0.88 0.025 145 / 0.09);
    --border-strong: oklch(0.39 0.038 145);
    --text-primary: oklch(0.96 0.01 90);
    --text-secondary: oklch(0.78 0.02 90);
    --accent-green: oklch(0.73 0.13 155);
    --accent-green-hover: oklch(0.79 0.12 155);
    --accent-terracotta: oklch(0.62 0.14 45);
    --success-green: oklch(0.72 0.14 135);
    --warning-amber: oklch(0.76 0.14 80);
    --danger: oklch(0.55 0.15 25);
    --text-on-green: oklch(0.14 0.02 90);

    --bg: var(--bg-base);
    --card: var(--surface);
    --panel: var(--surface-alt);
    --accent: var(--accent-green);
    --accent-hover: var(--accent-green-hover);
    --text: var(--text-primary);
    --text-muted: var(--text-secondary);
    --border: var(--border-strong);
    --radius: 8px;
    color-scheme: dark;
}

html.theme-light {
    --bg-base: oklch(0.965 0.012 105);
    --surface: oklch(0.995 0.006 100);
    --surface-deep: oklch(0.935 0.018 110);
    --surface-alt: oklch(0.91 0.022 115);
    --border-soft: oklch(0.28 0.035 140 / 0.10);
    --border-strong: oklch(0.73 0.035 125);
    --text-primary: oklch(0.21 0.03 140);
    --text-secondary: oklch(0.43 0.03 135);
    --accent-green: oklch(0.52 0.13 155);
    --accent-green-hover: oklch(0.45 0.12 155);
    --text-on-green: oklch(0.98 0.005 100);
    color-scheme: light;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-size: 14px;
}

.page-shell {
    width: min(760px, calc(100vw - 32px));
    margin: 0 auto;
    padding: 32px 0;
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 18px;
}

.back-link {
    display: inline-block;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 12px;
    margin-bottom: 6px;
    transition: color 0.2s;
}
.back-link:hover {
    color: var(--accent);
}

.eyebrow {
    margin: 0 0 4px;
    color: var(--text-muted);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    letter-spacing: 0.04em;
}

h1,
h2,
p {
    margin: 0;
}

h1 {
    color: var(--accent-hover);
    font-size: 28px;
    font-weight: 800;
}

h2 {
    font-size: 16px;
}

.panel {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

html.theme-light .panel {
    box-shadow: 0 12px 30px oklch(0.22 0.035 140 / 0.09);
}

.muted-panel {
    color: var(--text-muted);
}

.section-heading,
.master-toggle,
.inline-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.master-toggle,
.inline-toggle {
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.01em;
}

.preset-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
    gap: 10px;
    margin: 18px 0;
}

.preset-card {
    min-height: 44px;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.2s, box-shadow 0.2s;
}
.preset-card:hover {
    border-color: color-mix(in oklch, var(--accent), transparent 60%);
}

.preset-card:has(input:checked) {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px color-mix(in oklch, var(--accent), transparent 65%);
}

.preset-card input {
    accent-color: var(--accent);
}

.custom-grid {
    display: grid;
    gap: 12px;
    padding: 16px;
    background: var(--surface-deep);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius);
    transition: opacity 0.3s;
}

.control-row {
    display: grid;
    grid-template-columns: 110px minmax(160px, 1fr) 78px 30px;
    align-items: center;
    gap: 10px;
}

.control-row label {
    color: var(--text-muted);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.01em;
}

input[type="range"] {
    width: 100%;
    accent-color: var(--accent);
}

input[type="number"] {
    width: 100%;
    padding: 8px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    font: inherit;
    transition: border-color 0.2s;
}
input[type="number"]:focus {
    border-color: var(--accent);
    outline: none;
}

.unit {
    color: var(--text-muted);
    font-size: 12px;
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 38px;
    height: 22px;
    flex: 0 0 auto;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background-color: var(--border-strong);
    transition: .3s;
    border-radius: 22px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 3px;
    bottom: 3px;
    background-color: var(--text-secondary);
    transition: .3s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--accent);
}

input:checked + .slider:before {
    transform: translateX(16px);
    background-color: white;
}

@media (max-width: 620px) {
    .page-header,
    .section-heading {
        align-items: flex-start;
        flex-direction: column;
    }

    .control-row {
        grid-template-columns: 1fr 74px 28px;
    }

    .control-row label {
        grid-column: 1 / -1;
    }
}