:root {
    color-scheme: light dark;
    --bg: #f4f5f7;
    --surface: #ffffff;
    --text: #16181d;
    --muted: #61656e;
    --line: #dcdee3;
    --accent: #2f6df6;
    --accent-text: #ffffff;
    --danger: #b3261e;
    --danger-bg: #fdecea;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #14161a;
        --surface: #1c1f25;
        --text: #eceef2;
        --muted: #9aa0ab;
        --line: #2d313a;
        --accent: #5b8dff;
        --accent-text: #0b1220;
        --danger: #ff9a92;
        --danger-bg: #38201e;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 2rem 1rem;
    background: var(--bg);
    color: var(--text);
    font: 16px/1.55 system-ui, -apple-system, "Segoe UI", sans-serif;
}

.card {
    width: 100%;
    max-width: 26rem;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 2rem;
}

.brand {
    display: block;
    margin-bottom: 1.75rem;
    font-size: .95rem;
    font-weight: 700;
    letter-spacing: .04em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--muted);
}
.brand span { color: var(--accent); }

h1 { margin: 0 0 .35rem; font-size: 1.4rem; }
.sub { margin: 0 0 1.5rem; color: var(--muted); font-size: .93rem; }

label {
    display: block;
    margin-bottom: .3rem;
    font-size: .84rem;
    font-weight: 600;
    color: var(--muted);
}

input[type=text], input[type=email], input[type=password] {
    width: 100%;
    padding: .6rem .7rem;
    margin-bottom: 1rem;
    font: inherit;
    color: var(--text);
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: 8px;
}
input:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }

.row { display: flex; gap: .75rem; }
.row > div { flex: 1; }

button, .btn {
    display: block;
    width: 100%;
    padding: .65rem 1rem;
    font: inherit;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    background: var(--accent);
    color: var(--accent-text);
}
.btn-secondary {
    background: transparent;
    color: var(--text);
    border-color: var(--line);
}

.sep {
    display: flex;
    align-items: center;
    gap: .75rem;
    margin: 1.15rem 0;
    color: var(--muted);
    font-size: .8rem;
}
.sep::before, .sep::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.alt { margin: 1.5rem 0 0; font-size: .88rem; color: var(--muted); text-align: center; }
.alt a { color: var(--accent); }

.error {
    margin: 0 0 1.25rem;
    padding: .6rem .75rem;
    font-size: .88rem;
    color: var(--danger);
    background: var(--danger-bg);
    border-radius: 8px;
}
.error ul { margin: 0; padding-left: 1.1rem; }
.field-error { margin: -.75rem 0 1rem; font-size: .82rem; color: var(--danger); }

.notice {
    margin: 0 0 1.25rem;
    padding: .75rem;
    font-size: .88rem;
    color: var(--muted);
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: 8px;
}

.linked { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: 1rem; }
.linked form { margin: 0; }
.linked button { width: auto; padding: .35rem .7rem; font-size: .85rem; }

/* Two stacked calls to action, e.g. Sign in / Create account. */
.btn + .btn { margin-top: .75rem; }

footer {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--line);
    font-size: .82rem;
}
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--accent); text-decoration: underline; }

/* Long-form pages (the privacy policy) need more room than a sign-in form. */
.card:has(.prose) { max-width: 44rem; }

.prose h2 {
    margin: 1.75rem 0 .5rem;
    font-size: 1.02rem;
    letter-spacing: .01em;
}
.prose p, .prose li { color: var(--text); }
.prose ul { margin: .5rem 0 1rem; padding-left: 1.2rem; }
.prose li { margin-bottom: .35rem; }
.prose a { color: var(--accent); }
.prose .back { margin-top: 2rem; }