:root {
    --retro-bg: #222831;
    --retro-panel: #393e46;
    --retro-accent: #00fff5;
    --retro-pixel: #ffde59;
    --retro-text: #eeeeee;
    --retro-btn: #00fff5;
    --retro-btn-hover: #ffde59;
    --retro-shadow: 0 0 0 4px #00fff5, 0 0 0 8px #393e46;
    --retro-border: 4px solid #00fff5;
}

body {
    background: var(--retro-bg);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Press Start 2P', cursive;
    color: var(--retro-text);
    margin: 0;
    transition: background 0.3s, color 0.3s;
}

.light-mode {
    --retro-bg: #f3f3f3;
    --retro-panel: #fffbe6;
    --retro-accent: #222831;
    --retro-text: #eeeeee;
    --retro-btn: #ffde59;
    --retro-btn-hover: #00fff5;
    --retro-shadow: 0 0 0 4px #ffde59, 0 0 0 8px #fffbe6;
    --retro-border: 4px solid #ffde59;
}

.retro-container {
    background: var(--retro-panel);
    border: var(--retro-border);
    box-shadow: var(--retro-shadow);
    border-radius: 16px;
    padding: 40px 20px 24px 20px;
    max-width: 400px;
    width: 100%;
    text-align: center;
    position: relative;
}

.retro-logo {
    font-size: 2.5rem;
    color: var(--retro-pixel);
    margin-bottom: 10px;
    text-shadow: 2px 2px 0 #000, 0 0 8px var(--retro-pixel);
}

.retro-title {
    color: var(--retro-accent);
    font-size: 1.2rem;
    margin-bottom: 18px;
    letter-spacing: 2px;
    text-shadow: 2px 2px 0 #000, 0 0 8px var(--retro-accent);
}

.btn-retro {
    background: var(--retro-btn);
    color: #222831;
    border: 2px solid var(--retro-accent);
    border-radius: 8px;
    font-family: inherit;
    font-size: 1rem;
    padding: 8px 18px;
    margin-top: 10px;
    box-shadow: 2px 2px 0 #000, 0 0 8px var(--retro-btn);
    transition: background 0.2s, color 0.2s, box-shadow 0.2s;
}

.btn-retro:hover, .btn-retro:focus {
    background: var(--retro-btn-hover);
    color: #222831;
    box-shadow: 2px 2px 0 #000, 0 0 12px var(--retro-btn-hover);
}

.mode-toggle {
    position: absolute;
    top: 18px;
    right: 18px;
    background: transparent;
    border: none;
    color: var(--retro-accent);
    font-size: 1.3rem;
    cursor: pointer;
    transition: color 0.2s;
    z-index: 2;
}

.mode-toggle:hover {
    color: var(--retro-pixel);
}

.result {
    margin-top: 18px;
    min-height: 48px;
}

.footer-text {
    font-size: 0.7rem;
    color: var(--retro-accent);
    margin-top: 24px;
    opacity: 0.8;
    line-height: 1.6;
}

input.form-control-lg {
    font-size: 1rem;
    font-family: inherit;
    background: #23272f;
    color: var(--retro-text);
    border: 2px solid var(--retro-accent);
    border-radius: 8px;
    box-shadow: 1px 1px 0 #000;
    transition: border 0.2s, background 0.2s;
}

input.form-control-lg:focus {
    border-color: var(--retro-pixel);
    background: #2d323c;
    color: var(--retro-text);
}

@media (max-width: 500px) {
    .retro-container {
        padding: 18px 4px 14px 4px;
        max-width: 98vw;
    }
    .retro-title {
        font-size: 1rem;
    }
    .footer-text {
        font-size: 0.6rem;
    }
}