.st-utility-card {
    max-width: 700px;
    margin: 20px auto;
    background: #111827;
    border-radius: 16px;
    padding: 20px 22px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
    color: #e5e7eb;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.st-utility-header h3 {
    margin: 0 0 12px;
    font-size: 1.3rem;
    font-weight: 600;
    color: #f9fafb;
}

.st-utility-body {
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding-top: 14px;
}

.st-tool label {
    display: block;
    margin-bottom: 10px;
    font-size: 0.9rem;
    color: #d1d5db;
}

.st-tool input[type="text"],
.st-tool input[type="number"],
.st-tool input[type="date"],
.st-tool textarea,
.st-tool select {
    width: 100%;
    padding: 8px 10px;
    border-radius: 10px;
    border: 1px solid rgba(156, 163, 175, 0.5);
    background: rgba(17, 24, 39, 0.8);
    color: #f9fafb;
    font-size: 0.9rem;
    outline: none;
    box-sizing: border-box;
}

.st-tool textarea {
    resize: vertical;
}

.st-tool input:focus,
.st-tool textarea:focus,
.st-tool select:focus {
    border-color: #f97316;
    box-shadow: 0 0 0 1px rgba(249, 115, 22, 0.5);
}

.st-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    padding: 8px 18px;
    border: none;
    cursor: pointer;
    margin-top: 6px;
    margin-bottom: 10px;
    background: linear-gradient(135deg, #f97316, #fb923c);
    color: #111827;
    font-weight: 600;
    font-size: 0.9rem;
    transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}

.st-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.45);
}

.st-btn:active {
    transform: translateY(0);
    box-shadow: none;
}

.st-result {
    margin-top: 10px;
    padding: 10px 12px;
    border-radius: 12px;
    background: rgba(15, 23, 42, 0.85);
    border: 1px solid rgba(55, 65, 81, 0.8);
    font-size: 0.9rem;
}

.st-result strong {
    color: #fbbf24;
}

.st-result p {
    margin: 4px 0;
}

.st-checkbox {
    display: block;
    margin-bottom: 6px;
}

.st-checkbox input[type="checkbox"] {
    margin-right: 6px;
}

/* QR & barcode */
.st-qr-result,
.st-barcode-result {
    text-align: center;
}

.st-qrcode canvas {
    margin-top: 8px;
}

.st-barcode-svg {
    margin-top: 8px;
    max-width: 100%;
}

/* Color tools */
.st-color-picker-tool .st-color-preview {
    width: 100%;
    height: 40px;
    border-radius: 12px;
    margin-top: 8px;
    border: 1px solid rgba(75, 85, 99, 0.9);
}

.st-flex-row {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
}

.st-flex-row > div {
    flex: 1 1 220px;
}

/* Small screens */
@media (max-width: 600px) {
    .st-utility-card {
        padding: 16px;
        border-radius: 14px;
    }
}