styles.css

:root {
    --bg-color: #f0f0f0;
    --container-bg: #ffffff;
    --text-color: #333333;
    --button-bg: #4CAF50;
    --button-color: #ffffff;
    --button-hover: #45a049;
}

@media (prefers-color-scheme: dark) {
    :root:not(.light-mode):not(.dark-mode) {
        --bg-color: #121212;
        --container-bg: #1e1e1e;
        --text-color: #e0e0e0;
        --button-bg: #388E3C;
        --button-color: #ffffff;
        --button-hover: #2E7D32;
    }
}

.brainwave-state {
    margin-bottom: 1rem;
}

.brainwave-state label {
    display: block;
    margin-bottom: 0.5rem;
}

.brainwave-state select {
    width: 100%;
    padding: 0.5rem;
    font-size: 1rem;
    border-radius: 5px;
    background-color: var(--container-bg);
    color: var(--text-color);
    border: 1px solid var(--text-color);
}

.brainwave-state select:focus {
    outline: 2px solid var(--button-hover);
}

.dark-mode {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --button-bg: #388E3C;
    --button-color: #ffffff;
    --button-hover: #2E7D32;
}

.light-mode {
    --bg-color: #f0f0f0;
    --container-bg: #ffffff;
    --text-color: #333333;
    --button-bg: #4CAF50;
    --button-color: #ffffff;
    --button-hover: #45a049;
}

body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: background-color 0.3s;
}

h1 {
    color: var(--text-color);
}

label {
    display: block;
    margin-top: 1rem;
}

input[type="range"] {
    width: 100%;
    margin-top: 0.5rem;
}

button {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    background-color: var(--button-bg);
    color: var(--button-color);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: var(--button-hover);
}

button:focus {
    outline: 2px solid var(--button-hover);
}

.mode-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.toggle-checkbox {
    display: none;
}

.toggle-label {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 25px;
    background-color: var(--button-bg);
    border-radius: 25px;
    position: relative;
    transition: background-color 0.3s;
}

.toggle-label:before {
    content: '';
    position: absolute;
    width: 21px;
    height: 21px;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    background-color: var(--container-bg);
    transition: 0.3s;
}

.toggle-checkbox:checked+.toggle-label:before {
    transform: translateX(25px);
}

.sun-icon,
.moon-icon {
    position: absolute;
    width: 18px;
    height: 18px;
}

.sun-icon {
    left: 4px;
    opacity: 0;
    transition: opacity 0.3s;
}

.moon-icon {
    right: 4px;
    opacity: 1;
    transition: opacity 0.3s;
}

.toggle-checkbox:checked+.toggle-label .sun-icon {
    opacity: 1;
}

.toggle-checkbox:checked+.toggle-label .moon-icon {
    opacity: 0;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.brainwave-state-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.info-button {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    color: var(--text-color);
}

.info-button:hover {
    color: var(--button-hover);
}

.info-button:focus {
    outline: 2px solid var(--button-hover);
    border-radius: 50%;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: var(--container-bg);
    color: var(--text-color);
    padding: 2rem;
    border-radius: 10px;
    max-width: 40%;
    max-height: 80%;
    overflow-y: auto;
    position: relative;
}

.close-button {
    position: absolute;
    right: 1rem;
    top: 1rem;
    font-size: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-color);
}

.close-button:hover {
    color: var(--button-hover);
}

.close-button:focus {
    outline: 2px solid var(--button-hover);
    border-radius: 50%;
}

#modalContent ul {
    list-style-type: none;
    padding-left: 0;
}

#modalContent li {
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .modal-content {
        max-width: 90%;
        max-height: 90%;
        padding: 1.5rem;
    }

    .close-button {
        font-size: 2.5rem;
        padding: 0.5rem;
    }
}