/* General reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body, html {
    height: 100%;
    font-family: 'Arial', sans-serif;
}

/* Light theme styles */
:root {
    --background-color: #f0f8ff; /* Alice Blue */
    --text-color: #2f4f4f; /* Dark Slate Gray */
    --button-bg: #6a5acd; /* Slate Blue */
    --button-text-color: white;
    --input-bg: #e6e6fa; /* Lavender */
    --border-radius: 12px;
    --transition-time: 0.3s;
}

/* Body and general styles */
body {
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
    padding: 20px;
    font-size: 16px;
    transition: background-color var(--transition-time), color var(--transition-time);
}

.container {
    text-align: center;
    width: 100%;
    max-width: 450px;
    background-color: #ffffff; /* White */
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    padding: 30px;
    transition: all var(--transition-time);
}

h1, h2 {
    font-size: 26px;
    margin-bottom: 20px;
    color: var(--text-color);
}

button, select, input {
    padding: 12px;
    font-size: 16px;
    margin-bottom: 15px;
    border: none;
    border-radius: var(--border-radius);
    background-color: var(--input-bg);
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: background-color var(--transition-time), box-shadow var(--transition-time);
}

button {
    background-color: var(--button-bg);
    color: var(--button-text-color);
}

button:hover {
    background-color: #483d8b; /* Dark Slate Blue */
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

button.theme-btn {
    background-color: #20b2aa; /* Light Sea Green */
    color: white;
}

button.theme-btn:hover {
    background-color: #008080; /* Teal */
}

input, select {
    border: 1px solid #ccc;
    background-color: var(--input-bg);
}

input:focus, select:focus {
    border-color: var(--button-bg);
    outline: none;
    box-shadow: 0 0 5px rgba(106, 90, 205, 0.8); /* Slate Blue glow */
}

.qr-code-container img, .qr-history-container img {
    margin-top: 20px;
    max-width: 100%;
    height: auto;
}

.qr-history-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}

.qr-history-container img {
    width: 80px;
    height: 80px;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* Dark theme styles */
body.dark-theme {
    background-color: #1e1e2f; /* Dark Indigo */
    color: #d1d1e9; /* Light Lavender */
}

body.dark-theme .container {
    background-color: #252538; /* Soft Navy */
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

body.dark-theme input, select, button {
    background-color: #33334d; /* Deep Navy */
    color: white;
    border: 1px solid #55556f;
}

body.dark-theme input:focus, body.dark-theme select:focus {
    border-color: #6a5acd; /* Slate Blue */
    box-shadow: 0 0 5px rgba(106, 90, 205, 0.8); /* Slate Blue glow */
}

body.dark-theme button {
    background-color: #ff6347; /* Tomato */
}

body.dark-theme button:hover {
    background-color: #e5533c; /* Darker Tomato */
}

/* Responsive Styles */
@media (max-width: 600px) {
    .container {
        padding: 20px;
        width: 90%;
    }

    h1, h2 {
        font-size: 22px;
    }

    button, select, input {
        width: 100%;
    }
}