:root {
    --bg: #050505;
    --text: #e0e0e0;
    --accent: #bc13fe; /* Cyberpunk Purple */
    --box-bg: #111;
    --box-border: #333;
    --box-active: #555;
}

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

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Space Grotesk', sans-serif;
    min-height: 100vh;
    display: flex; flex-direction: column;
}

/* NAV */
.top-nav { padding: 20px; }
.nav-back {
    font-family: 'Space Mono', monospace; font-size: 0.8rem;
    color: var(--text); text-decoration: none; opacity: 0.6;
    transition: opacity 0.2s;
}
.nav-back:hover { opacity: 1; color: var(--accent); }

/* LAYOUT */
.solver-container {
    width: 90%; max-width: 800px;
    margin: 2rem auto;
    text-align: center;
}

header h1 {
    font-family: 'Space Mono', monospace;
    font-size: 2.5rem; letter-spacing: -1px;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
}
header p {
    font-family: 'Space Mono', monospace;
    font-size: 0.8rem; color: #777;
    margin-bottom: 2rem;
}

/* CONTROLS (Toggle Switch) */
.controls {
    margin-bottom: 30px;
    display: flex; justify-content: center; align-items: center; gap: 15px;
    font-family: 'Space Mono', monospace; font-size: 0.8rem; color: #888;
}

/* The Switch Box */
.toggle-switch {
    position: relative; display: inline-block; width: 50px; height: 24px;
}
.toggle-switch input { opacity: 0; width: 0; height: 0; }

/* The Slider */
.slider {
    position: absolute; cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: #333; transition: .4s; border-radius: 24px;
}
.slider:before {
    position: absolute; content: "";
    height: 16px; width: 16px; left: 4px; bottom: 4px;
    background-color: white; transition: .4s; border-radius: 50%;
}

input:checked + .slider { background-color: var(--accent); }
input:checked + .slider:before { transform: translateX(26px); }

/* GRID */
.grid-wrapper {
    display: flex; justify-content: center; gap: 6px;
    margin-bottom: 2rem; flex-wrap: nowrap; width: 100%;
}

.letter-box {
    flex: 1 1 45px; max-width: 50px; height: 60px;
    background: var(--box-bg); border: 2px solid var(--box-border);
    border-radius: 6px; color: #fff;
    font-family: 'Space Grotesk', sans-serif;
    font-size: clamp(1rem, 2.5vw, 2rem);
    font-weight: 700; text-align: center; text-transform: uppercase;
    outline: none; transition: all 0.2s; padding: 0;
    caret-color: var(--accent);
}

.letter-box:focus {
    border-color: var(--accent);
    box-shadow: 0 0 15px rgba(188, 19, 254, 0.3);
    transform: translateY(-5px);
}
.letter-box.filled { background: #1a0526; border-color: #555; }

/* ACTIONS */
.action-row {
    display: flex; justify-content: center; gap: 15px; margin-top: 2rem;
}

.solve-btn {
    background: var(--text); color: var(--bg);
    border: none; padding: 15px 30px;
    font-family: 'Space Mono', monospace; font-size: 1rem; font-weight: bold;
    cursor: pointer; border-radius: 4px;
    transition: transform 0.1s, background 0.2s;
}
.solve-btn:hover { background: var(--accent); transform: scale(1.05); }
.solve-btn:active { transform: scale(0.95); }

.clear-btn {
    background: transparent; border: 1px solid #444; color: #888;
    padding: 15px 25px;
    font-family: 'Space Mono', monospace; font-size: 1rem;
    cursor: pointer; border-radius: 4px; transition: all 0.2s;
}
.clear-btn:hover { border-color: #ff4444; color: #ff4444; }

/* RESULTS */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 10px; margin-top: 3rem; padding-top: 2rem;
    border-top: 1px dashed #333;
}

.result-item {
    background: #111; padding: 10px;
    border: 1px solid #222; color: var(--accent);
    font-family: 'Space Mono', monospace; font-size: 0.9rem;
    cursor: pointer; transition: background 0.2s;
}
.result-item:hover { background: #222; border-color: var(--accent); color: #fff; }

/* Mobile */
@media (max-width: 600px) {
    header h1 { font-size: 1.8rem; }
    .grid-wrapper { flex-wrap: wrap; }
    .letter-box { flex: 0 0 45px; margin-bottom: 5px; }
}