:root {
    --bg: #0f172a;
    --bg-accent: #111827;
    --card: #0b1220;
    --text: #e5e7eb;
    --muted: #9ca3af;
    --primary: #2563eb;
    --primary-600: #1d4ed8;
    --ring: rgba(37, 99, 235, 0.4);
    --error: #ef4444;
    --border: #1f2937;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100svh;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
    color: var(--text);
    background: radial-gradient(1200px 600px at 10% 10%, #0b1220 0%, var(--bg) 50%, var(--bg-accent) 100%);
    display: grid;
    place-items: center;
    padding: 24px;
}

.container {
    width: 100%;
    max-width: 720px;
    display: grid;
    gap: 20px;
}

.card {
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.02));
    border: 1px solid var(--border);
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.04);
    padding: 28px;
    backdrop-filter: saturate(130%) blur(8px);
}

header h1 {
    margin: 0 0 6px;
    font-size: 28px;
    letter-spacing: 0.2px;
}

header p {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

form {
    margin-top: 8px;
    display: grid;
    gap: 16px;
}

.grid {
    display: grid;
    gap: 16px;
}

@media (min-width: 640px) {
    .grid.two-col {
        grid-template-columns: 1fr 1fr;
    }
}

.field {
    display: grid;
    gap: 6px;
}

label {
    font-size: 13px;
    color: var(--muted);
}

input[type="text"],
input[type="email"],
input[type="number"] {
    width: 100%;
    appearance: none;
    background: rgba(17, 24, 39, 0.6);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 12px 14px;
    outline: none;
    transition: border-color .2s, box-shadow .2s, background .2s;
}

input::placeholder {
    color: #6b7280;
}

input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 6px var(--ring);
    background: rgba(17, 24, 39, 0.9);
}

input:invalid:focus {
    border-color: var(--error);
    box-shadow: 0 0 0 6px rgba(239, 68, 68, 0.3);
}

/* Select (dropdown) */
select {
    width: 100%;
    background: rgba(17, 24, 39, 0.6);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 12px 40px 12px 14px; /* room for caret */
    outline: none;
    transition: border-color .2s, box-shadow .2s, background .2s, color .2s;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%239CA3AF' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 18px 18px;
}

select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 6px var(--ring);
    background: rgba(17, 24, 39, 0.9);
}

/* Show muted text when placeholder option (empty value) is selected */
select:required:invalid { color: #6b7280; }

/* Checkbox */
input[type="checkbox"] {
    width: 18px;
    height: 18px;
    border-radius: 4px;
    vertical-align: middle;
    accent-color: var(--primary);
    outline: none;
}

/* Layout tweaks when a checkbox is inside a field */
.field:has(input[type="checkbox"]) {
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    align-items: center;
    gap: 6px 10px;
}

.field input[type="checkbox"] { margin-right: 8px; }
.field:has(input[type="checkbox"]) label { align-self: center; }
.field:has(input[type="checkbox"]) small { grid-column: 2 / 3; margin-top: -2px; }

/* Helper text */
small { color: var(--muted); font-size: 12px; }

.actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 4px;
}

button[type="submit"] {
    background: linear-gradient(180deg, var(--primary), var(--primary-600));
    color: white;
    border: 0;
    padding: 12px 16px;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(37, 99, 235, 0.35);
    transition: transform .06s ease, filter .2s ease, box-shadow .2s ease;
}

button[type="submit"]:hover {
    filter: brightness(1.05);
    box-shadow: 0 10px 24px rgba(37, 99, 235, 0.45);
}

button[type="submit"]:active {
    transform: translateY(1px);
}

footer {
    text-align: center;
    color: var(--muted);
    font-size: 12px;
}