/* Tối ưu cho màn hình rộng (max-width: 1000px) */
.tool-container {
    font-family: 'Inter', 'Montserrat', system-ui, sans-serif;
    max-width: 1000px;
    margin: 20px auto;
    border: 3px solid #000000;
    border-radius: 12px;
    box-shadow: 8px 8px 0px #000000;
    padding: 30px;
    background: #fff;
    color: #000000;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 20px;
}

.advanced-settings {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 20px;
    background-color: #f4f4f4;
    padding: 20px;
    border: 3px solid #000000;
    border-radius: 8px;
    margin-bottom: 20px;
    align-items: end;
}

.input-group label, .adv-col label {
    display: block;
    font-weight: 900;
    margin-bottom: 8px;
    font-size: 1rem;
    color: #000;
}

.input-group input[type="number"], .adv-col select {
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
    font-weight: 800;
    border: 3px solid #000000;
    border-radius: 8px;
    outline: none;
    background-color: #ffffff;
    box-shadow: 3px 3px 0px #000000;
}

.checkbox-container {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-weight: 900;
    font-size: 1.05rem;
    height: 48px;
    color: #000;
}
.checkbox-container input { margin-right: 10px; width: 22px; height: 22px; cursor: pointer; accent-color: #000; }

.action-buttons {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 15px;
    margin-bottom: 25px;
}

.action-buttons button {
    cursor: pointer;
    font-size: 1.2rem;
    font-weight: 900;
    padding: 15px;
    border: 3px solid #000000;
    border-radius: 8px;
    box-shadow: 4px 4px 0px #000000;
    transition: transform 0.1s, box-shadow 0.1s;
    text-transform: uppercase;
    color: #000000;
}

.action-buttons button:active:not(:disabled) {
    transform: translate(4px, 4px);
    box-shadow: 0px 0px 0px #000000;
}

.btn-generate { background-color: #ffdac1; }
.btn-copy { background-color: #cbaacb; }

.result-box {
    background-color: #e2f0cb;
    border: 3px solid #000000;
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: inset 0px 0px 10px rgba(0,0,0,0.05);
}

.number-output {
    font-weight: 900;
    font-size: 35px;
    color: #000000;
    word-break: break-all;
    line-height: 1.4;
}

.history-box {
    margin-top: 25px;
    padding: 15px;
    background-color: #f9f9f9;
    border: 2px dashed #000000;
    border-radius: 8px;
}