/* === Additions-Tabelle — extends theme-math.css === */

.card::before { content: '➕'; }

.btn-check {
    background: linear-gradient(135deg, #27AE60, #52BE80);
    box-shadow: 0 4px 15px rgba(39, 174, 96, 0.4);
    width: auto;
    margin-top: 0;
    padding: 0.5rem 1.5rem;
    font-size: 1rem;
}

.btn-new {
    background: linear-gradient(135deg, var(--math-tertiary), #7FC8F8);
    box-shadow: 0 4px 15px rgba(93, 173, 226, 0.4);
    width: auto;
    padding: 0.75rem 2rem;
    font-size: 1rem;
}

.table-wrapper {
    overflow-x: auto;
    padding: 0.5rem 0;
    -webkit-overflow-scrolling: touch;
}

.addition-grid {
    display: grid;
    gap: 5px;
    width: fit-content;
    margin: 0 auto;
}

.grid-cell {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    font-family: 'Fredoka', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    position: relative;
}

/* Animate only the cells that actually change state */
.header-cell,
.result-cell {
    transition: transform 0.15s ease, box-shadow 0.15s ease,
                background 0.15s ease, border-color 0.15s ease;
}

.corner-cell {
    background: linear-gradient(135deg, var(--math-primary), #FF8CB4);
    color: white;
    font-size: 1.8rem;
    pointer-events: none;
}

.header-cell {
    background: linear-gradient(135deg, #FFF3CD, #FFE082);
    color: var(--text-dark);
    border: 2px solid #FFC107;
    pointer-events: none;
}

.header-cell.highlighted {
    background: linear-gradient(135deg, var(--math-secondary), #FFD54F);
    border-color: #FF8F00;
    transform: scale(1.12);
    box-shadow: 0 4px 14px rgba(254, 194, 96, 0.6);
    z-index: 2;
}

.header-cell.hidden-header {
    background: white;
    border: 2px dashed #FFC107;
    pointer-events: auto;
}

.header-cell.hidden-header.correct {
    background: linear-gradient(135deg, #D5F4E6, #ABEBC6);
    border: 2px solid #27AE60;
}

.header-cell.hidden-header.incorrect {
    background: linear-gradient(135deg, #FADBD8, #F5B7B1);
    border: 2px solid #E74C3C;
}

.result-cell {
    background: white;
    border: 2px solid #E0E0E0;
}

.result-cell.prefilled {
    background: linear-gradient(135deg, #E3F2FD, #BBDEFB);
    border-color: #5DADE2;
    color: #1565C0;
}

.result-cell.prefilled.hint-full {
    background: linear-gradient(135deg, #FFF9C4, #FFF176);
    border-color: #F9A825;
    transform: scale(1.08);
    box-shadow: 0 4px 12px rgba(249, 168, 37, 0.5);
    z-index: 2;
}

.result-cell.prefilled.hint-medium {
    background: linear-gradient(135deg, #FFFDE7, #FFF9C4);
    border-color: #FFC107;
    transform: scale(1.04);
    box-shadow: 0 2px 6px rgba(255, 193, 7, 0.3);
    z-index: 2;
}

.result-cell.prefilled.hint-faint {
    border-color: #FFD54F;
    transform: scale(1.02);
}

.result-cell.correct {
    background: linear-gradient(135deg, #D5F4E6, #ABEBC6);
    border-color: #27AE60;
}

.result-cell.incorrect {
    background: linear-gradient(135deg, #FADBD8, #F5B7B1);
    border-color: #E74C3C;
}

.grid-cell input {
    width: 100%;
    height: 100%;
    border: none;
    background: transparent;
    text-align: center;
    font-family: 'Fredoka', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-dark);
    outline: none;
    padding: 0;
    -moz-appearance: textfield;
    cursor: pointer;
}

.grid-cell input::-webkit-inner-spin-button,
.grid-cell input::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.grid-cell input:focus {
    color: var(--math-primary);
}

.table-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.hint-bar {
    text-align: center;
    font-size: 1rem;
    color: #888;
    margin-top: 1rem;
    font-style: italic;
}

@media (max-width: 600px) {
    .grid-cell {
        width: 42px;
        height: 42px;
        font-size: 1.1rem;
        border-radius: 8px;
    }

    .corner-cell { font-size: 1.3rem; }
    .grid-cell input { font-size: 1.1rem; }
    .addition-grid { gap: 3px; }
}