:root {
    --background-color: #f0f2f5;
    --container-background: #fff;
    --text-color: #333;
    --header-color: #1a73e8;
    --subheader-color: #5f6368;
    --button-background: #1a73e8;
    --button-text: white;
    --history-item-background: #f8f9fa;
    --radial-gradient-start: #ffffff;
    --radial-gradient-end: #f0f2f5;
}

[data-theme='dark'] {
    --background-color: #121212;
    --container-background: #1e1e1e;
    --text-color: #e0e0e0;
    --header-color: #bb86fc;
    --subheader-color: #b0bec5;
    --button-background: #bb86fc;
    --button-text: #121212;
    --history-item-background: #2c2c2c;
    --radial-gradient-start: #1e1e1e;
    --radial-gradient-end: #121212;
}

body {
    font-family: 'Helvetica Neue', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-image: radial-gradient(circle, var(--radial-gradient-start), var(--radial-gradient-end));
    transition: background-color 0.3s, color 0.3s;
}

.container {
    background: var(--container-background);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 600px;
    width: 90%;
    transition: background-color 0.3s;
}

h1 {
    color: var(--header-color);
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

#menu-display {
    margin: 2rem 0;
    padding: 1rem;
    border: 2px dashed var(--header-color);
    border-radius: 8px;
    min-height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#menu-display p {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-color);
}

#recommend-btn {
    background-color: var(--button-background);
    color: var(--button-text);
    border: none;
    padding: 1rem 2rem;
    font-size: 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

#recommend-btn:hover {
    filter: brightness(1.2);
    transform: translateY(-2px);
}

.history {
    margin-top: 2rem;
}

h2 {
    color: var(--subheader-color);
    border-bottom: 2px solid #ddd;
    padding-bottom: 0.5rem;
}

#recommendation-history {
    list-style: none;
    padding: 0;
    max-height: 200px;
    overflow-y: auto;
}

#recommendation-history li {
    background: var(--history-item-background);
    padding: 0.75rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.theme-switch-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
}

.theme-switch input {
    display:none;
}

.slider {
    background-color: #ccc;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
}

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 26px;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}