.fz-sdk-wrapper {
    max-width: 480px;
    margin: 0 auto;
}
.fz-sdk-diff-group {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.fz-sdk-diff-btn {
    border-radius: 2rem;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 0.35rem 0.9rem;
    border: 1.5px solid var(--bs-border-color, #dee2e6);
    background: var(--bs-body-bg, #fff);
    color: var(--bs-body-color, #212529);
    transition: all 0.15s ease;
    cursor: pointer;
}
.fz-sdk-diff-btn:hover {
    border-color: var(--bs-primary, #0d6efd);
    color: var(--bs-primary, #0d6efd);
}
.fz-sdk-diff-btn.active {
    background: var(--bs-primary, #0d6efd);
    border-color: var(--bs-primary, #0d6efd);
    color: #fff;
    box-shadow: 0 2px 8px rgba(13, 110, 253, 0.3);
}
.fz-sdk-hud {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bs-tertiary-bg, #f8f9fa);
    border: 1px solid var(--bs-border-color, #dee2e6);
    border-radius: 0.5rem;
    padding: 0.5rem 1rem;
    margin-bottom: 1rem;
}
.fz-sdk-grid-wrapper {
    position: relative;
    width: 100%;
    max-width: 450px;
    margin: 0 auto 1rem auto;
}
.fz-sdk-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    grid-template-rows: repeat(9, 1fr);
    gap: 1.5px;
    background: #64748b;
    border: 3.5px solid #1e293b;
    border-radius: 0.5rem;
    overflow: hidden;
    margin: 0 auto 1rem auto;
    width: 100%;
    max-width: 450px;
    aspect-ratio: 1 / 1;
    min-height: 340px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation;
}
.fz-sdk-cell {
    width: 100%;
    height: 100%;
    min-height: 35px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    font-weight: 700;
    background-color: #ffffff;
    color: #0f172a;
    cursor: pointer;
    position: relative;
    transition: background-color 0.12s ease;
}
.fz-sdk-cell.fz-sdk-box-right {
    border-right: 3px solid #1e293b !important;
}
.fz-sdk-cell.fz-sdk-box-bottom {
    border-bottom: 3px solid #1e293b !important;
}
.fz-sdk-cell.given {
    font-weight: 800;
    color: #0f172a !important;
    background-color: #f8fafc;
}
.fz-sdk-cell.user-val {
    color: #0284c7 !important;
    font-weight: 700;
}
.fz-sdk-cell.highlighted {
    background-color: #f0f9ff !important;
}
.fz-sdk-cell.same-digit {
    background-color: #dcfce7 !important;
}
.fz-sdk-cell.selected {
    background-color: #bae6fd !important;
    outline: 2.5px solid #0284c7;
    z-index: 5;
}
.fz-sdk-cell.error {
    background-color: #ffe4e6 !important;
    color: #e11d48 !important;
    animation: fz-shake 0.3s ease;
}
[data-bs-theme="dark"] .fz-sdk-grid {
    background: #475569;
    border-color: #0f172a;
}
[data-bs-theme="dark"] .fz-sdk-cell {
    background-color: #1e293b;
    color: #f8fafc;
}
[data-bs-theme="dark"] .fz-sdk-cell.fz-sdk-box-right {
    border-right-color: #0f172a !important;
}
[data-bs-theme="dark"] .fz-sdk-cell.fz-sdk-box-bottom {
    border-bottom-color: #0f172a !important;
}
[data-bs-theme="dark"] .fz-sdk-cell.given {
    color: #ffffff !important;
    background-color: #0f172a;
}
[data-bs-theme="dark"] .fz-sdk-cell.user-val {
    color: #38bdf8 !important;
}
[data-bs-theme="dark"] .fz-sdk-cell.highlighted {
    background-color: #1e3a5f !important;
}
[data-bs-theme="dark"] .fz-sdk-cell.same-digit {
    background-color: #064e3b !important;
}
[data-bs-theme="dark"] .fz-sdk-cell.selected {
    background-color: #0369a1 !important;
    outline-color: #38bdf8;
}
.fz-sdk-notes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    width: 100%;
    height: 100%;
    padding: 1px;
    pointer-events: none;
}
.fz-sdk-note-num {
    font-size: 0.65rem;
    font-weight: 600;
    color: var(--bs-secondary-color, #6c757d);
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}
.fz-sdk-tools {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 0.75rem;
}
.fz-sdk-tool-btn {
    flex: 1;
    max-width: 120px;
    padding: 0.4rem 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 0.5rem;
    border: 1px solid var(--bs-border-color, #dee2e6);
    background: var(--bs-body-bg, #fff);
    color: var(--bs-body-color, #212529);
    cursor: pointer;
    transition: all 0.15s;
}
.fz-sdk-tool-btn:hover {
    background: var(--bs-tertiary-bg, #f8f9fa);
    border-color: var(--bs-primary, #0d6efd);
}
.fz-sdk-tool-btn.active {
    background: var(--bs-warning-bg-subtle, #fff3cd);
    border-color: var(--bs-warning, #ffc107);
    color: var(--bs-emphasis-color, #000);
}
.fz-sdk-keypad {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 6px;
    max-width: 450px;
    margin: 0 auto 1rem auto;
}
.fz-sdk-key-btn {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 700;
    border-radius: 0.5rem;
    border: 1.5px solid var(--bs-border-color, #dee2e6);
    background: var(--bs-body-bg, #fff);
    color: var(--bs-primary, #0d6efd);
    cursor: pointer;
    transition: transform 0.1s, background-color 0.15s;
    user-select: none;
    padding: 0;
}
.fz-sdk-key-btn:hover:not(:disabled) {
    background-color: var(--bs-primary-bg-subtle, #cfe2ff);
    transform: translateY(-2px);
    border-color: var(--bs-primary, #0d6efd);
}
.fz-sdk-key-btn:active:not(:disabled) {
    transform: scale(0.95);
}
.fz-sdk-key-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}
@media (max-width: 576px) {
    .fz-sdk-grid {
        max-width: 350px;
        min-height: 280px;
    }
    .fz-sdk-cell {
        font-size: 1.15rem;
    }
    .fz-sdk-note-num {
        font-size: 0.5rem;
    }
    .fz-sdk-keypad {
        gap: 4px;
        max-width: 350px;
    }
    .fz-sdk-key-btn {
        font-size: 1.1rem;
    }
}