:root {
    --fg-color: #00FF41;
    --glow-color: #00FF41;
    --bg-color: #0a0a0a;
    --panel-bg: #0d0d0d;
    --border-color: #1a1a1a;
    --color-stack: #00CED1;
    --color-vreg: #00FF41;
    --color-ireg: #FFD700;
    --color-timer: #FF6B35;
    --color-pc: #FF69B4;
    --color-sp: #E0E0E0;
}

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

body {
    background: #030303;
    color: var(--fg-color);
    font-family: 'JetBrains Mono', monospace;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 12px;
    overflow-x: hidden;
}

#app {
    max-width: 900px;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
}

header {
    text-align: center;
    padding: 16px 0 4px;
}

header h1 {
    font-family: 'Press Start 2P', monospace;
    font-size: 24px;
    color: var(--fg-color);
    text-shadow: 0 0 8px var(--glow-color), 0 0 16px var(--glow-color);
    letter-spacing: 3px;
}

header .subtitle {
    display: block;
    margin-top: 6px;
    font-size: 10px;
    color: #666;
    letter-spacing: 2px;
    text-transform: uppercase;
}

#controls {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    justify-content: center;
    padding: 10px 12px;
    background: var(--panel-bg);
    border: 1px solid #1a1a1a;
    border-radius: 4px;
    width: 100%;
}

.rom-btn {
    position: relative;
    cursor: pointer;
    background: #111;
    border: 1px solid var(--fg-color);
    color: var(--fg-color);
    padding: 7px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    font-weight: 700;
    border-radius: 3px;
    transition: all 0.15s;
}

.rom-btn:hover {
    background: var(--fg-color);
    color: #000;
    box-shadow: 0 0 8px var(--glow-color);
}

.rom-btn input[type="file"] {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    opacity: 0;
    cursor: pointer;
    width: 100%;
}

.ctrl-btn {
    background: #111;
    border: 1px solid #333;
    color: #aaa;
    padding: 7px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    font-weight: 500;
    border-radius: 3px;
    cursor: pointer;
    transition: all 0.15s;
}

.ctrl-btn:hover {
    border-color: var(--fg-color);
    color: var(--fg-color);
    box-shadow: 0 0 5px var(--glow-color);
}

.ctrl-btn:active {
    background: var(--fg-color);
    color: #000;
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 10px;
    color: #666;
}

.speed-control input[type="range"] {
    width: 70px;
    accent-color: var(--fg-color);
}

.speed-control span {
    color: var(--fg-color);
    min-width: 18px;
    text-align: center;
}

.demo-btns {
    display: flex;
    gap: 5px;
}

.demo-btn {
    background: transparent;
    border: 1px solid #333;
    color: #777;
    padding: 5px 9px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    border-radius: 3px;
    cursor: pointer;
    transition: all 0.15s;
}

.demo-btn:hover {
    border-color: var(--fg-color);
    color: var(--fg-color);
}

#display-wrapper {
    width: 100%;
    display: flex;
    justify-content: center;
}

#crt-bezel {
    position: relative;
    border: 3px solid #1a1a1a;
    border-radius: 10px;
    padding: 6px;
    background: #040404;
    box-shadow:
        inset 0 0 20px rgba(0,0,0,0.9),
        0 0 10px rgba(0,0,0,0.5),
        0 0 2px var(--glow-color);
    overflow: hidden;
}

#screen {
    display: block;
    border-radius: 3px;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
    width: 100%;
    max-width: 640px;
    height: auto;
}

#scanlines {
    position: absolute;
    top: 6px; left: 6px; right: 6px; bottom: 6px;
    border-radius: 3px;
    pointer-events: none;
    background: repeating-linear-gradient(
        0deg, transparent, transparent 2px,
        rgba(0, 0, 0, 0.12) 2px, rgba(0, 0, 0, 0.12) 4px
    );
    z-index: 2;
}

#status-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 6px 14px;
    background: var(--panel-bg);
    border: 1px solid #1a1a1a;
    border-radius: 4px;
    font-size: 10px;
    color: #555;
    width: 100%;
    justify-content: center;
}

#status-bar span { white-space: nowrap; }

.sound-on {
    color: var(--fg-color) !important;
    text-shadow: 0 0 6px var(--glow-color);
    animation: pulse 0.5s infinite alternate;
}

.sound-off { color: #333 !important; }

@keyframes pulse {
    from { opacity: 0.6; }
    to { opacity: 1; }
}

#settings-row {
    display: flex;
    gap: 14px;
    align-items: center;
    font-size: 10px;
    color: #666;
    flex-wrap: wrap;
    justify-content: center;
}

#settings-row select {
    background: #111;
    border: 1px solid #333;
    color: var(--fg-color);
    padding: 3px 6px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    border-radius: 3px;
    cursor: pointer;
}

#settings-row input[type="checkbox"] {
    accent-color: var(--fg-color);
}

#main-lower {
    display: flex;
    gap: 14px;
    width: 100%;
    align-items: flex-start;
    flex-wrap: wrap;
}

#keyboard {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    width: 280px;
    min-width: 240px;
    padding: 10px;
    background: var(--panel-bg);
    border: 1px solid #1a1a1a;
    border-radius: 6px;
    flex-shrink: 0;
}

.key {
    aspect-ratio: 1;
    font-family: 'Press Start 2P', monospace;
    font-size: 14px;
    background: #111;
    border: 2px solid #252525;
    border-bottom: 3px solid #333;
    color: #666;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.08s;
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation;
    display: flex;
    align-items: center;
    justify-content: center;
}

.key:hover {
    border-color: var(--fg-color);
    color: var(--fg-color);
    box-shadow: 0 0 6px var(--glow-color);
}

.key.active, .key:active {
    background: var(--fg-color) !important;
    color: #000 !important;
    border-color: var(--fg-color) !important;
    box-shadow: 0 0 12px var(--glow-color), inset 0 0 4px rgba(0,0,0,0.3) !important;
    transform: translateY(1px);
    border-bottom-width: 2px;
}

/* Debug Panel */
#debug-panel {
    flex: 1;
    min-width: 300px;
    background: var(--panel-bg);
    border: 1px solid #1a1a1a;
    border-radius: 6px;
    padding: 12px;
    font-size: 10px;
    overflow-x: auto;
}

.debug-section {
    margin-bottom: 12px;
}

.debug-section h3 {
    font-size: 9px;
    font-weight: 500;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 6px;
    color: #555;
}

.title-registers { color: var(--color-vreg) !important; }
.title-scalar { color: #888 !important; }
.title-stack { color: var(--color-stack) !important; }
.title-hexdump { color: #888 !important; }

.section-title { border-bottom: 1px solid #1a1a1a; padding-bottom: 4px; }

/* Memory map bar */
#memory-map-bar {
    display: flex;
    height: 14px;
    border-radius: 3px;
    overflow: hidden;
    border: 1px solid #222;
    margin-bottom: 8px;
}

.map-segment {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 7px;
    font-weight: 700;
    letter-spacing: 0.5px;
    color: #000;
}

.seg-font { background: #555; flex: 0.08; }
.seg-reserved { background: #222; flex: 0.17; }
.seg-program { background: #1a5c1a; flex: 0.64; color: #aaffaa; }
.seg-registers { background: #FFD700; flex: 0.07; color: #333; }
.seg-free { background: #1a1a2e; flex: 0.04; }

/* V-Register grid */
.register-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 3px;
}

.reg-cell {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 3px 2px;
    background: #0a0a0a;
    border: 1px solid #1a1a1a;
    border-radius: 3px;
}

.reg-label {
    font-size: 8px;
    color: #555;
    margin-bottom: 1px;
}

.reg-val {
    font-size: 11px;
    font-weight: 700;
    color: var(--color-vreg);
}

.flash-vreg { color: #fff !important; text-shadow: 0 0 6px var(--color-vreg); }
.flash-ireg { color: #fff !important; text-shadow: 0 0 6px var(--color-ireg); }
.flash-timer { color: #fff !important; text-shadow: 0 0 6px var(--color-timer); }
.flash-sp { color: #fff !important; text-shadow: 0 0 6px var(--color-sp); }

/* Scalar registers */
.scalar-row {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 2px 0;
    border-bottom: 1px solid #0f0f0f;
}

.scalar-row .reg-label {
    min-width: 22px;
    font-size: 9px;
    font-weight: 700;
}

.scalar-row .reg-val {
    min-width: 30px;
    font-size: 11px;
}

.color-stack { color: var(--color-stack) !important; }
.color-vreg { color: var(--color-vreg) !important; }
.color-ireg { color: var(--color-ireg) !important; }
.color-timer { color: var(--color-timer) !important; }
.color-pc { color: var(--color-pc) !important; }
.color-sp { color: var(--color-sp) !important; }

.timer-bar {
    flex: 1;
    height: 4px;
    background: #1a1a1a;
    border-radius: 2px;
    overflow: hidden;
    max-width: 60px;
}

.timer-fill {
    height: 100%;
    background: var(--color-timer);
    transition: width 0.1s;
    border-radius: 2px;
}

.timer-fill-sound {
    background: #FF3333;
}

/* Debug row layout */
.debug-row {
    display: flex;
    gap: 12px;
}

.debug-col {
    flex: 1;
    min-width: 0;
}

/* Stack view */
#stack-view {
    display: flex;
    flex-direction: column;
    gap: 1px;
}

.stack-entry {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 1px 4px;
    font-size: 9px;
    color: #333;
    background: #080808;
    border-radius: 2px;
}

.stack-entry.active-stack {
    color: var(--color-stack);
    background: #0a1515;
}

.stack-level {
    color: #444;
    min-width: 10px;
}

.stack-val {
    font-weight: 700;
}

.stack-ptr {
    color: var(--color-stack);
    font-size: 8px;
    animation: pulse 0.6s infinite alternate;
}

/* Hex dump */
.hex-dump {
    font-size: 9px;
    line-height: 1.6;
}

.hex-row {
    display: flex;
    gap: 3px;
    flex-wrap: nowrap;
}

.hex-addr {
    color: #444;
    min-width: 28px;
    margin-right: 6px;
}

.hex-byte {
    min-width: 16px;
    text-align: center;
}

.hex-stack { color: var(--color-stack); }
.hex-vreg { color: var(--color-vreg); }
.hex-ireg { color: var(--color-ireg); }
.hex-timer { color: var(--color-timer); }
.hex-pc { color: var(--color-pc); }
.hex-sp { color: var(--color-sp); }
.hex-free { color: #222; }

/* About Section */
#about-section {
    width: 100%;
    font-size: 11px;
    color: #555;
    border: 1px solid #1a1a1a;
    border-radius: 4px;
    padding: 10px 14px;
    background: var(--panel-bg);
}

#about-section summary {
    cursor: pointer;
    color: #777;
    font-weight: 500;
    outline: none;
}

#about-section summary:hover { color: var(--fg-color); }

#about-section p {
    margin-top: 8px;
    line-height: 1.6;
}

#about-section ul {
    margin-top: 6px;
    padding-left: 18px;
    line-height: 1.8;
}

#about-section code {
    background: #1a1a1a;
    padding: 1px 4px;
    border-radius: 2px;
    color: var(--fg-color);
}

#about-section strong { color: #aaa; }

footer {
    padding: 14px 0;
    text-align: center;
}

footer a {
    color: #444;
    text-decoration: none;
    font-size: 10px;
    transition: color 0.2s;
}

footer a:hover { color: var(--fg-color); }

/* Responsive */
@media (max-width: 700px) {
    #main-lower {
        flex-direction: column;
        align-items: center;
    }

    #keyboard {
        width: 100%;
        max-width: 320px;
    }

    #debug-panel {
        min-width: unset;
        width: 100%;
    }

    .debug-row {
        flex-direction: column;
    }

    header h1 { font-size: 18px; }

    .hex-row { font-size: 8px; }
    .hex-byte { min-width: 14px; }
}

@media (max-width: 400px) {
    body { padding: 6px; }
    #controls { gap: 5px; padding: 8px; }
    .ctrl-btn, .rom-btn { padding: 5px 8px; font-size: 9px; }
    .key { font-size: 12px; }
}