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

:root {
    --bg: #f4f4f5;
    --card: #ffffff;
    --ink: #18181b;
    --subtle: #71717a;
    --line: #e4e4e7;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --danger: #dc2626;
    --danger-hover: #b91c1c;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,.08), 0 8px 24px rgba(0,0,0,.06);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #18181b;
        --card: #27272a;
        --ink: #f4f4f5;
        --subtle: #a1a1aa;
        --line: #3f3f46;
        --accent: #3b82f6;
        --accent-hover: #2563eb;
        --shadow: 0 1px 3px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
    }
}

body.dark-mode {
    --bg: #18181b;
    --card: #27272a;
    --ink: #f4f4f5;
    --subtle: #a1a1aa;
    --line: #3f3f46;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --shadow: 0 1px 3px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
}

body.light-mode {
    --bg: #f4f4f5;
    --card: #ffffff;
    --ink: #18181b;
    --subtle: #71717a;
    --line: #e4e4e7;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --shadow: 0 1px 3px rgba(0,0,0,.08), 0 8px 24px rgba(0,0,0,.06);
}

body {
    min-height: 100vh;
    background: var(--bg);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    font-size: 14px;
    color: var(--ink);
    display: grid;
    grid-template-rows: 1fr auto;
    place-items: center;
    padding: 24px 16px 0;
}

/* ── Layout ── */
.shell {
    width: min(100%, 400px);
    padding-bottom: 24px;
}

footer {
    width: 100%;
    padding: 16px;
    text-align: center;
    font-size: 12px;
    color: var(--subtle);
}

footer a {
    color: var(--subtle);
    text-decoration: none;
}

footer a:hover { color: var(--ink); }

/* ── Brand ── */
.brand {
    text-align: center;
    margin-bottom: 20px;
}

.brand-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--ink);
    letter-spacing: -0.01em;
}

/* ── Card ── */
.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 28px;
}

.card-title {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 4px;
}

.card-subtitle {
    font-size: 13px;
    color: var(--subtle);
    margin-bottom: 20px;
    line-height: 1.5;
}

hr {
    border: none;
    border-top: 1px solid var(--line);
    margin: 20px 0;
}

/* ── Form ── */
.stack { display: grid; gap: 12px; }

.field { display: grid; gap: 5px; }

.field span {
    font-size: 13px;
    font-weight: 500;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 9px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--card);
    font: inherit;
    font-size: 14px;
    color: var(--ink);
    outline: none;
    transition: border-color 120ms, box-shadow 120ms;
}

input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(37,99,235,.12);
}

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 9px 16px;
    border: none;
    border-radius: 8px;
    font: inherit;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: background 120ms, box-shadow 120ms;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
}

.btn-primary:hover { background: var(--accent-hover); }

.btn-secondary {
    background: transparent;
    color: var(--ink);
    border: 1px solid var(--line);
}

.btn-secondary:hover { background: var(--bg); }

.btn-danger {
    background: var(--danger);
    color: #fff;
}

.btn-danger:hover { background: var(--danger-hover); }

/* ── Alert ── */
.alert {
    padding: 9px 12px;
    border-radius: 8px;
    font-size: 13px;
    line-height: 1.4;
    margin-bottom: 16px;
}

.alert-error {
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

/* ── Info table ── */
.info-table { width: 100%; border-collapse: collapse; }

.info-table tr + tr td { border-top: 1px solid var(--line); }

.info-table td {
    padding: 9px 0;
    font-size: 13px;
    vertical-align: top;
    line-height: 1.5;
}

.info-table td:first-child {
    color: var(--subtle);
    width: 36%;
    padding-right: 12px;
}

/* ── Badge ── */
.badge {
    display: inline-block;
    padding: 1px 8px;
    border-radius: 99px;
    font-size: 12px;
    font-weight: 500;
    background: #eff6ff;
    color: var(--accent);
    border: 1px solid #dbeafe;
    margin: 2px 2px 2px 0;
}

/* ── Dark mode toggle ── */
#dark-mode-toggle {
    position: fixed;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid var(--line);
    background: var(--card);
    color: var(--subtle);
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 120ms, color 120ms, border-color 120ms;
    z-index: 999;
    text-decoration: none;
}
#dark-mode-toggle:hover {
    background: var(--bg);
    color: var(--ink);
}