:root {
    /* Captain America Light Theme */
    --bg-color: #f0f0f0; /* Light grey background */
    --text-color: #1c3a5e; /* Dark blue text */
    --container-bg: #ffffff; /* White container */
    --container-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
    --header-color: #d90429; /* Strong red for headers */
    --header-shadow: #1c3a5e; /* Dark blue shadow */
    --subheader-color: #1c3a5e; /* Dark blue for subheaders */
    --placeholder-bg: #e9ecef;
    --placeholder-border: #adb5bd;
    --placeholder-text: #6c757d;
    --survey-border: #d90429; /* Red survey border */
    --slider-bg: #ced4da;
    --stripe-color: rgba(28, 58, 94, 0.05); /* Subtle dark blue stripes */
}

body.dark-mode {
    /* Avengers Dark Theme */
    --bg-color: #0d1b2a; /* Very dark blue background */
    --text-color: #e0e1dd; /* Off-white text */
    --container-bg: #1b263b; /* Lighter dark blue container */
    --container-shadow: 0 0 15px rgba(239, 35, 60, 0.2);
    --header-color: #ef233c; /* Brighter red for headers */
    --header-shadow: #000;
    --subheader-color: #adb5bd; /* Silver/grey for subheaders */
    --placeholder-bg: #415a77;
    --placeholder-border: #778da9;
    --placeholder-text: #e0e1dd;
    --survey-border: #ef233c; /* Red survey border */
    --slider-bg: #415a77;
    --stripe-color: rgba(224, 225, 221, 0.04); /* Subtle light stripes */
}

body {
    font-family: 'Bangers', 'Ubuntu', sans-serif;
    font-size: 1.25em; /* Increase font size by 25% */
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    transition: background-color 0.3s, color 0.3s;
    background-image: repeating-linear-gradient(
        45deg,
        transparent,
        transparent 15px,
        var(--stripe-color) 15px,
        var(--stripe-color) 30px
    );
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--container-bg);
    padding: 20px;
    border-radius: 10px;
    box-shadow: var(--container-shadow);
    transition: background-color 0.3s;
}

h1 {
    text-align: center;
    color: var(--header-color);
    text-shadow: 2px 2px var(--header-shadow);
    position: relative; /* For pseudo-element positioning */
}

h1::before, h1::after {
    content: "★";
    font-size: 0.8em;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    color: var(--subheader-color);
    text-shadow: 1px 1px 2px var(--header-shadow);
}

h1::before {
    left: .5em;
}

h1::after {
    right: .5em;
}

.party-details {
    margin-bottom: 20px;
}

.party-details h2 {
    color: var(--subheader-color);
}

.birthday-girl-image {
    width: 100%;
    max-width: 400px;
    height: auto;
    margin: 20px auto;
    display: block;
    background-color: var(--placeholder-bg);
    border: 2px dashed var(--placeholder-border);
    text-align: center;
    line-height: 200px;
    font-size: 20px;
    color: var(--placeholder-text);
}

#surveyContainer {
    padding: 20px;
    border: 2px solid var(--survey-border);
    border-radius: 5px;
    font-family: 'Bangers', 'Ubuntu', sans-serif !important;
}

/* Theme Toggle Switch */
.theme-switch-wrapper {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    align-items: center;
}

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

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    background-color: var(--slider-bg);
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "☀️";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 26px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    color: #1c3a5e;
}

input:checked + .slider {
    background-color: #ef233c; /* Use the theme's bright red/pink for the slider */
}

input:checked + .slider:before {
    transform: translateX(26px);
    content: "🌙";
    color: var(--container-bg); /* Use the dark container color for the moon icon */
}

/* Improve link visibility in dark mode */
body.dark-mode .party-details a {
    color: #87CEEB; /* A nice, readable sky blue */
}