:root {
    --cell-size: 140px;
    --grid-gap: 12px;
    --toss-blue: #0000BC;
    --mandarat-color: var(--toss-blue);
    --gradient-start: var(--mandarat-color);
    --gradient-end: color-mix(in srgb, var(--mandarat-color) 60%, white);
}

:root[data-bs-theme="light"] {
    --bg-color: #ffffff;
    --text-color: #6c757d;
    --border-color: rgba(0, 0, 0, 0.1);
    --card-bg: #ffffff;
    --input-bg: #ffffff;
    --alert-bg: rgba(13, 202, 240, 0.1);
    --hover-shadow: rgba(0, 0, 0, 0.1);
    --placeholder-color: #495057;  /* Darker gray for better visibility */
}

:root[data-bs-theme="dark"] {
    --bg-color: var(--bs-dark);
    --text-color: var(--bs-light);
    --border-color: rgba(255, 255, 255, 0.1);
    --card-bg: var(--bs-dark);
    --input-bg: var(--bs-dark);
    --alert-bg: rgba(13, 202, 240, 0.1);
    --hover-shadow: rgba(0, 0, 0, 0.3);
    --placeholder-color: #6c757d;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 2rem;
}

.theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
    background: none;
    border: 1px solid var(--border-color);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    color: var(--text-color);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    transform: translateY(-2px);
    box-shadow: 0 2px 8px var(--hover-shadow);
}

.mandarat-grid {
    display: grid;
    grid-template-columns: repeat(3, var(--cell-size));
    grid-template-rows: repeat(3, var(--cell-size));
    gap: var(--grid-gap);
    margin: 0 auto;
    max-width: calc(3 * var(--cell-size) + 2 * var(--grid-gap));
}

.mandarat-cell {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-size: 1rem;
    line-height: 1.4;
    min-height: var(--cell-size);
    transition: all 0.2s ease;
    word-break: break-word;
    cursor: pointer;
    color: var(--text-color);
}

.mandarat-cell.placeholder {
    opacity: 0.85;  /* Increased opacity for better visibility */
    color: var(--placeholder-color);
    font-size: 0.9rem;
    font-style: italic;
}

.mandarat-cell:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--hover-shadow);
}

.mandarat-cell.central {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    font-weight: 600;
    border: none;
    transition: all 0.3s ease;
}

.grid-input {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.alert {
    max-width: 800px;
    margin: 0 auto 2rem;
    border-radius: 16px;
    padding: 24px;
    background-color: var(--alert-bg);
    border: none;
    color: var(--text-color);
}

.card {
    border-radius: 20px;
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    height: 100%;
    box-shadow: 0 4px 6px var(--hover-shadow);
}

.card-body {
    padding: 32px;
}

.form-control {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 12px 16px;
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.2s ease;
}

.form-control:focus {
    background-color: var(--input-bg);
    border-color: var(--toss-blue);
    box-shadow: 0 0 0 2px rgba(0, 0, 188, 0.2);
    color: var(--text-color);
}

.btn-primary {
    background-color: var(--toss-blue);
    border: none;
    border-radius: 12px;
    padding: 12px 24px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-primary:hover {
    background-color: #0000d6;
    transform: translateY(-1px);
}

.display-5 {
    font-weight: 700;
    margin-bottom: 1.5rem;
    font-size: 2.5rem;
    color: var(--text-color);
}

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6 {
    color: var(--text-color);
}

@media (max-width: 768px) {
    :root {
        --cell-size: 100px;
    }

    .grid-input {
        grid-template-columns: 1fr;
    }

    .container {
        padding: 1rem;
    }

    .display-5 {
        font-size: 2rem;
    }

    .card-body {
        padding: 24px;
    }
}

/* Input in mandarat cell */
.mandarat-cell input.form-control {
    width: 100%;
    height: 100%;
    background: transparent;
    border: none;
    text-align: center;
    padding: 8px;
    color: inherit;
}

.mandarat-cell input.form-control:focus {
    outline: none;
    box-shadow: none;
}

/* Add styles for download button */
#downloadBtn {
    border-color: var(--toss-blue);
    color: var(--toss-blue);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

#downloadBtn:hover {
    background-color: var(--toss-blue);
    color: white;
    transform: translateY(-1px);
}

#downloadBtn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#downloadBtn i {
    width: 18px;
    height: 18px;
}

/* Add styles for color picker */
.form-control-color {
    width: 100px;
    height: 40px;
    padding: 0;
    border-radius: 8px;
}