body {
    font-family: sans-serif;
}

#board.solved-feedback {
    animation: solved-board-glow 900ms ease-out;
}

.puzzle-status {
    min-height: 1.5em;
    margin-top: 8px;
    font-weight: 700;
}

.puzzle-status.solved-feedback {
    animation: solved-message-pop 1600ms ease-out;
    color: #176d31;
}

.help-dialog {
    max-width: 560px;
    border: 1px solid #333;
    border-radius: 8px;
    padding: 0;
}

.help-dialog::backdrop {
    background: rgb(0 0 0 / 0.45);
}

.help-dialog form {
    padding: 20px;
}

.help-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 12px;
}

.help-header h2 {
    margin: 0;
}

.help-dialog p {
    margin: 0 0 12px;
    line-height: 1.45;
}

.help-dialog ul {
    margin: 0;
    padding-left: 24px;
    line-height: 1.45;
}

@keyframes solved-board-glow {
    0% {
        box-shadow: 0 0 0 0 rgb(39 174 96 / 0);
    }

    30% {
        box-shadow: 0 0 0 6px rgb(39 174 96 / 0.85), 0 0 22px 8px rgb(255 214 102 / 0.8);
    }

    100% {
        box-shadow: 0 0 0 0 rgb(39 174 96 / 0);
    }
}

@keyframes solved-message-pop {
    0% {
        opacity: 0;
        transform: translateY(-4px);
    }

    15% {
        opacity: 1;
        transform: translateY(0);
    }

    80% {
        opacity: 1;
    }

    100% {
        opacity: 0;
    }
}