:root {
    --bg-color: #121212;
    --primary-color: #1e1e1e;
    --accent-color: #00ff7f;
    --text-color: #e0e0e0;
    --secondary-text-color: #a0a0a0;
    --border-color: #444;
    --button-text-color: #121212;
    --shadow-color: rgba(0, 255, 127, 0.1);
}

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

body {
    font-family: 'Segoe UI', 'Roboto', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 1rem;
}

.container {
    background-color: var(--primary-color);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 8px 25px var(--shadow-color);
    text-align: center;
    width: 100%;
    max-width: 420px;
    border: 1px solid var(--border-color);
}

h1 {
    color: var(--accent-color);
    margin-bottom: 0.75rem;
    font-size: 2rem;
    font-weight: 600;
}

p {
    color: var(--secondary-text-color);
    margin-bottom: 2rem;
}

#qr-text {
    width: 100%;
    padding: 12px;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
}

#qr-text:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 10px var(--shadow-color);
}

#generate-btn,
#download-btn {
    background-color: var(--accent-color);
    color: var(--button-text-color);
    border: none;
    padding: 14px 22px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    text-decoration: none;
    display: inline-block;
}

#generate-btn:hover,
#download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 255, 127, 0.2);
}

#download-btn {
    display: none;
    margin-top: 1.5rem;
}

#qr-code-container {
    margin-top: 2rem;
    padding: 1rem;
    background-color: #fff;
    border-radius: 8px;
    min-height: 256px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#qr-code-container img {
    max-width: 100%;
    border-radius: 4px;
}

/* Custom Alert Styles */
.alert-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: none; /* Hidden by default */
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.alert-box {
    background-color: var(--primary-color);
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
    text-align: center;
    width: 90%;
    max-width: 380px;
    animation: fadeIn 0.3s ease-out;
}

.alert-box h2 {
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.alert-box p {
    margin-bottom: 1.5rem;
}

#alert-ok-btn {
    background-color: var(--accent-color);
    color: var(--button-text-color);
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: background-color 0.3s;
}

#alert-ok-btn:hover {
    background-color: #00cc66; /* A slightly different shade for hover */
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}