.text-code-widget {
    margin-top: 1.2rem;
    padding: 1.4rem;
    border: 1px solid #dbeafe;
    border-radius: 22px;
    background: linear-gradient(135deg, #f8fbff, #eef6ff);
    box-shadow: 0 14px 35px rgba(15, 23, 42, 0.08);
}

.widget-control-row,
.speed-control-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.8rem;
    margin-bottom: 1rem;
}

.widget-control-row label,
.speed-control-row label {
    font-weight: 700;
    color: #1e293b;
}

.widget-control-row input,
.widget-control-row select {
    min-width: 180px;
    padding: 0.7rem 0.85rem;
    border: 1px solid #cbd5e1;
    border-radius: 14px;
    font-size: 1rem;
    background: #ffffff;
}

.widget-control-row button {
    border: 0;
    border-radius: 999px;
    padding: 0.7rem 1rem;
    font-weight: 700;
    cursor: pointer;
    background: #2563eb;
    color: #ffffff;
    box-shadow: 0 8px 18px rgba(37, 99, 235, 0.22);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.widget-control-row button:hover {
    transform: translateY(-1px);
    box-shadow: 0 12px 22px rgba(37, 99, 235, 0.28);
}

.speed-control-row input[type="range"] {
    width: 220px;
}

#utf8SpeedLabel {
    font-weight: 700;
    color: #475569;
}

.ascii-result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(155px, 1fr));
    gap: 0.9rem;
    margin: 1rem 0;
}

.code-result-card,
.utf8-summary > div {
    padding: 1rem;
    border-radius: 18px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.06);
}

.code-label {
    display: block;
    margin-bottom: 0.35rem;
    font-size: 0.78rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #64748b;
}

.code-result-card strong,
.utf8-summary strong {
    font-size: 1.25rem;
    color: #0f172a;
    word-break: break-word;
}

.bit-strip {
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
    margin: 1rem 0;
}

.bit-cell {
    width: 42px;
    height: 48px;
    border-radius: 14px;
    display: grid;
    place-items: center;
    background: #e0f2fe;
    border: 1px solid #bae6fd;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-weight: 800;
    color: #0f172a;
    transition: transform 0.25s ease, background 0.25s ease;
}

.bit-cell.active {
    transform: translateY(-4px) scale(1.04);
    background: #bfdbfe;
    border-color: #60a5fa;
}

.ascii-note-box,
.utf8-step-explanation {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 18px;
    background: #fff7ed;
    border: 1px solid #fed7aa;
    color: #7c2d12;
    font-weight: 600;
}

.utf8-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(165px, 1fr));
    gap: 0.9rem;
    margin: 1rem 0;
}

.utf8-byte-stage {
    display: flex;
    flex-wrap: wrap;
    gap: 0.9rem;
    margin-top: 1rem;
}

.utf8-byte-card {
    min-width: 170px;
    flex: 1;
    padding: 1rem;
    border-radius: 20px;
    background: #ffffff;
    border: 1px solid #dbeafe;
    box-shadow: 0 10px 22px rgba(15, 23, 42, 0.07);
    opacity: 0.45;
    transform: translateY(6px);
    transition: opacity 0.35s ease, transform 0.35s ease, border-color 0.35s ease;
}

.utf8-byte-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.utf8-byte-card.current {
    border-color: #2563eb;
    box-shadow: 0 14px 28px rgba(37, 99, 235, 0.18);
}

.utf8-byte-title {
    display: flex;
    justify-content: space-between;
    gap: 0.8rem;
    align-items: center;
    margin-bottom: 0.7rem;
}

.utf8-byte-title strong {
    color: #1e293b;
}

.utf8-byte-type {
    font-size: 0.75rem;
    font-weight: 800;
    padding: 0.25rem 0.55rem;
    border-radius: 999px;
    background: #dbeafe;
    color: #1d4ed8;
}

.utf8-bits {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}

.utf8-bit {
    width: 24px;
    height: 30px;
    display: grid;
    place-items: center;
    border-radius: 9px;
    background: #f1f5f9;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-weight: 800;
    color: #334155;
}

.utf8-bit.prefix {
    background: #dbeafe;
    color: #1d4ed8;
}

.utf8-bit.payload {
    background: #dcfce7;
    color: #166534;
}

.utf8-hex-line {
    margin-top: 0.8rem;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    color: #475569;
    font-weight: 700;
}

.converter-error {
    color: #b91c1c;
    font-weight: 700;
    margin: 0.4rem 0;
}

.formula-line {
    padding: 0.8rem 1rem;
    border-radius: 16px;
    background: #f1f5f9;
    border: 1px solid #e2e8f0;
}

.exam-tip-box,
.warning-box {
    margin: 1rem 0;
    padding: 1rem;
    border-radius: 18px;
}

.exam-tip-box {
    background: #ecfdf5;
    border: 1px solid #bbf7d0;
    color: #14532d;
}

.warning-box {
    background: #fff7ed;
    border: 1px solid #fed7aa;
    color: #7c2d12;
}

@media (max-width: 640px) {
    .widget-control-row,
    .speed-control-row {
        align-items: stretch;
        flex-direction: column;
    }

    .widget-control-row input,
    .widget-control-row select,
    .widget-control-row button,
    .speed-control-row input[type="range"] {
        width: 100%;
    }

    .bit-cell {
        width: 36px;
        height: 42px;
    }
}