:root {
    --header-height: 3.5em;

    --font: sans-serif;
    --border-radius: 0.25em;
    --base-spacing: 1rem;

    --color-background: #f4f5f7;
    --color-card-background: #ffffff;
    --color-card-background-secondary: #eceef1;
    --color-border: #d5d9df;
    --color-text: #1a1b1e;
    --color-text-muted: #5c6370;
    --color-primary: #3b6fd4;
    --color-primary-text: #ffffff;
    --color-danger: #cc3344;
    --color-success: #2f9e44;
    --color-warning: #e8a13a;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #1a1b1e;
        --color-card-background: #25262b;
        --color-card-background-secondary: #2e2f34;
        --color-border: #3a3b40;
        --color-text: #e9ecef;
        --color-text-muted: #a0a6b0;
        --color-primary: #5a8dee;
        --color-primary-text: #0b1220;
        --color-danger: #ff6b7d;
        --color-success: #51cf66;
        --color-warning: #ffc061;
        --shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
    }
}

:root[data-theme="light"] {
    --color-background: #f4f5f7;
    --color-card-background: #ffffff;
    --color-card-background-secondary: #eceef1;
    --color-border: #d5d9df;
    --color-text: #1a1b1e;
    --color-text-muted: #5c6370;
    --color-primary: #3b6fd4;
    --color-primary-text: #ffffff;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
}

:root[data-theme="dark"] {
    --color-background: #1a1b1e;
    --color-card-background: #25262b;
    --color-card-background-secondary: #2e2f34;
    --color-border: #3a3b40;
    --color-text: #e9ecef;
    --color-text-muted: #a0a6b0;
    --color-primary: #5a8dee;
    --color-primary-text: #0b1220;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font);
    background: var(--color-background);
    color: var(--color-text);
    min-height: 100vh;
}

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

/* --- App shell ------------------------------------------------------- */

.app-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    gap: var(--base-spacing);
    padding: 0 var(--base-spacing);
    background: var(--color-card-background);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 20;
}

.app-header .title {
    font-weight: bold;
}

.app-header .spacer {
    flex: 1;
}

.app-body {
    display: flex;
    align-items: flex-start;
}

nav {
    width: 30ch;
    flex-shrink: 0;
    padding: var(--base-spacing);
    border-right: 1px solid var(--color-border);
    background: var(--color-card-background);
    min-height: calc(100vh - var(--header-height));
}

nav a {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.6rem 0.8rem;
    margin-bottom: 0.4rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--color-text);
    font-weight: 500;
}

nav a.brand {
    color: var(--brand-text, #fff);
    background: var(--brand, var(--color-primary));
}

.source-select a.brand {
    color: var(--brand-text, #fff);
    background: var(--brand, var(--color-primary));
}

main {
    flex: 1;
    padding: calc(var(--base-spacing) * 1.5);
    width: 100%;
    height: calc(100vh - var(--header-height));
    overflow-y: auto;
}

/* mobile nav hidden by default */
.burger {
    display: none;
    background: none;
    border: none;
    color: var(--color-text);
    font-size: 1.4rem;
    cursor: pointer;
}

#nav-toggle {
    display: none;
}

@media (max-width: 48em) {
    .burger {
        display: block;
    }
    nav {
        display: none;
        width: 100%;
        min-height: auto;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
    }
    #nav-toggle:checked ~ .app-body nav {
        display: block;
    }
    .app-body {
        flex-direction: column;
    }
    main {
        padding: var(--base-spacing);
    }
}

/* --- Basic form styling for server-rendered pages -------------------- */

.stack {
    display: flex;
    flex-direction: column;
    gap: var(--base-spacing);
}

h1 {
    font-size: 1.6rem;
    margin: 0 0 0.5rem;
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.3rem;
}

input[type="text"],
input[type="password"],
input[type="url"],
input[type="file"] {
    width: 100%;
    padding: 0.55rem 0.7rem;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    background: var(--color-card-background);
    color: var(--color-text);
    font: inherit;
}

nav a:hover {
    background: color-mix(in oklab, var(--brand, var(--color-card-background)), color-mix(in oklab, var(--color-primary), grey) 30%);
}

.source-select a:hover {
    background: color-mix(in oklab, var(--brand, var(--color-card-background)), color-mix(in oklab, var(--color-primary), grey) 30%);
}

.field-errors {
    color: var(--color-danger);
    font-size: 0.9rem;
    margin-top: 0.3rem;
}