:root {
    --bg: #f4f5f9;
    --surface: #ffffff;
    --surface-2: #f0f1f6;
    --text: #1b1d29;
    --muted: #666b80;
    --border: #dcdfe8;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --accent-soft: #e8e7fd;
    --on-accent: #ffffff;
    --danger: #c42b2b;
    --danger-soft: #fdecec;
    --warn: #9a5b00;
    --success: #1f7a3d;
    --radius: 12px;
    --shadow: 0 1px 2px rgb(16 24 40 / 6%), 0 8px 24px rgb(16 24 40 / 6%);
    color-scheme: light;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f1117;
        --surface: #181b24;
        --surface-2: #11131a;
        --text: #e8eaf2;
        --muted: #9a9fb3;
        --border: #2c3040;
        --accent: #7c74ff;
        --accent-hover: #918aff;
        --accent-soft: #25234a;
        --on-accent: #ffffff;
        --danger: #ff6b6b;
        --danger-soft: #3a1c1f;
        --warn: #f0b64a;
        --success: #5fd08a;
        --shadow: 0 1px 2px rgb(0 0 0 / 40%), 0 8px 24px rgb(0 0 0 / 30%);
        color-scheme: dark;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--bg);
    color: var(--text);
    font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, sans-serif;
}

[hidden] { display: none !important; }

.topbar { padding: 18px 16px; max-width: 720px; width: 100%; margin: 0 auto; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 650; font-size: 17px; }

.wrap { flex: 1; width: 100%; max-width: 720px; margin: 0 auto; padding: 0 16px 32px; }

.foot { text-align: center; color: var(--muted); font-size: 13px; padding: 16px; }

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 28px;
}
.card.center { text-align: center; }
.card.center .btn { margin-top: 8px; }

h1 { margin: 0 0 4px; font-size: 22px; line-height: 1.3; letter-spacing: -0.01em; }
.lead { margin: 0 0 22px; color: var(--muted); }
.meta { display: flex; flex-wrap: wrap; gap: 4px 18px; }
.muted { color: var(--muted); font-weight: 400; }
.small { font-size: 13px; }
.hint { margin: 6px 0 0; font-size: 13px; color: var(--muted); }
.warn { color: var(--warn); }
.error { margin: 0 0 14px; padding: 10px 12px; border-radius: 8px; background: var(--danger-soft); color: var(--danger); font-size: 14px; }
.success { margin: 14px 0 0; color: var(--success); font-weight: 550; }

.field { margin: 0 0 20px; }
fieldset.field { border: 0; padding: 0; min-width: 0; }
label, legend { display: block; font-weight: 600; margin-bottom: 6px; padding: 0; }
.label-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; margin-bottom: 6px; }
.label-row > label { margin: 0; }
.gen { display: flex; align-items: center; gap: 8px; }
.gen label { margin: 0; }

input[type=text], input[type=password], input[type=number], textarea, select {
    width: 100%;
    font: inherit;
    color: var(--text);
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 12px;
    transition: border-color .15s, box-shadow .15s;
}
textarea { resize: vertical; font-family: ui-monospace, "Cascadia Mono", Menlo, Consolas, monospace; font-size: 14px; }
input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}
.gen-length { width: 68px !important; padding: 5px 8px !important; }

.input-group { display: flex; gap: 8px; }
.input-group input { flex: 1; min-width: 0; }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 16px; }

.segmented {
    display: grid;
    grid-template-columns: 1fr 1fr;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 4px;
    gap: 4px;
}
.segmented input { position: absolute; opacity: 0; pointer-events: none; }
.segmented label {
    margin: 0;
    text-align: center;
    padding: 9px 10px;
    border-radius: 7px;
    cursor: pointer;
    font-weight: 500;
    color: var(--muted);
    transition: background .15s, color .15s;
}
.segmented label:hover { color: var(--text); }
.segmented input:checked + label { background: var(--accent); color: var(--on-accent); }
.segmented input:focus-visible + label { box-shadow: 0 0 0 3px var(--accent-soft); }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font: inherit;
    font-weight: 600;
    border-radius: 8px;
    padding: 10px 16px;
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: background .15s, border-color .15s, color .15s;
}
.btn:disabled { opacity: .6; cursor: default; }
.btn-primary { background: var(--accent); color: var(--on-accent); }
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); }
.btn-danger { background: transparent; color: var(--danger); border-color: var(--danger); white-space: normal; text-align: center; }
.btn-danger:hover:not(:disabled) { background: var(--danger-soft); }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-lg { padding: 13px 22px; font-size: 16px; width: 100%; margin-top: 14px; }

.actions { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; margin-top: 8px; }
.spacer { flex: 1; }

.badge { display: inline-block; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 99px; margin-bottom: 10px; }
.badge-muted { background: var(--surface-2); color: var(--muted); border: 1px solid var(--border); }

.secret-box { position: relative; }
.secret-box pre {
    margin: 0;
    padding: 16px 80px 16px 16px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    font: 14px/1.5 ui-monospace, "Cascadia Mono", Menlo, Consolas, monospace;
    white-space: pre-wrap;
    word-break: break-all;
    max-height: 60vh;
    overflow: auto;
}
.copy-secret { position: absolute; top: 10px; right: 10px; background: var(--surface); }
#revealed .actions { margin-top: 20px; }

@media (max-width: 560px) {
    .card { padding: 20px 16px; }
    .grid-2, .segmented { grid-template-columns: 1fr; }
    .spacer { display: none; }
}