/* ==========================================================================
   Retro486 Browser Emulator - Core Layout & CRT Monitor Styles
   ========================================================================== */

:root {
    --bg-dark: #0e1116;
    --bg-panel: #171c24;
    --bg-card: #1f2631;
    --bezel-plastic: #2b3038;
    --bezel-inner: #181b20;
    --accent-green: #00ff66;
    --accent-amber: #ffaa00;
    --accent-cyan: #33ccff;
    --accent-red: #ff4444;
    --text-primary: #e6edf3;
    --text-muted: #8b949e;
    --border-color: #30363d;
    --led-off: #222a24;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: 'Courier New', Courier, monospace;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* ==========================================================================
   Top System Header & Navigation Tabs
   ========================================================================== */

#top-header {
    background: #13171e;
    border-bottom: 2px solid var(--border-color);
    padding: 10px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}

.brand-box {
    display: flex;
    align-items: center;
    gap: 12px;
}

.cpu-badge {
    background: linear-gradient(135deg, #1f4e3d, #0f291e);
    color: var(--accent-green);
    border: 1px solid var(--accent-green);
    padding: 4px 10px;
    border-radius: 4px;
    font-weight: bold;
    font-size: 14px;
    letter-spacing: 0.5px;
    box-shadow: 0 0 10px rgba(0, 255, 102, 0.2);
}

.system-title {
    font-size: 16px;
    font-weight: bold;
    color: #fff;
}

.top-telemetry {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 12px;
    background: #0b0e12;
    padding: 6px 14px;
    border-radius: 6px;
    border: 1px solid #262c36;
}

.post-pill {
    background: #2a1215;
    color: #ff5555;
    border: 1px solid #661e26;
    padding: 2px 7px;
    border-radius: 3px;
    font-weight: bold;
}

#nav-tabs-bar {
    background: #161b22;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    flex-wrap: wrap;
}

.nav-tabs-left {
    display: flex;
    gap: 4px;
}

.nav-tab-btn {
    background: transparent;
    color: var(--text-muted);
    border: none;
    border-bottom: 3px solid transparent;
    padding: 12px 18px;
    font-family: inherit;
    font-size: 13px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.15s ease;
}

.nav-tab-btn:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.03);
}

.nav-tab-btn.active {
    color: var(--accent-green);
    border-bottom-color: var(--accent-green);
    background: rgba(0, 255, 102, 0.06);
}

.nav-actions-right {
    display: flex;
    gap: 8px;
    padding: 6px 0;
}

/* ==========================================================================
   Tab Panes Container
   ========================================================================== */

#main-workspace {
    flex: 1;
    padding: 20px;
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
}

.tab-pane {
    display: none;
    animation: fadeIn 0.15s ease-in-out;
}

.tab-pane.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(3px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   Tab 1: Period-Correct CRT Monitor View
   ========================================================================== */

.monitor-workspace {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

#monitor-bezel {
    background: linear-gradient(145deg, #323741, #22262e);
    padding: 36px 44px 24px 44px;
    border-radius: 22px;
    border: 4px solid #434a56;
    box-shadow:
        0 20px 50px rgba(0, 0, 0, 0.85),
        inset 0 2px 4px rgba(255, 255, 255, 0.12),
        inset 0 -4px 8px rgba(0, 0, 0, 0.6);
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 880px;
    width: 100%;
}

.crt-frame-inner {
    background: #000000;
    padding: 0;
    border-radius: 16px;
    border: 6px solid #1a1d24;
    box-shadow: inset 0 0 32px #000;
    width: 100%;
    display: flex;
    justify-content: center;
    overflow: hidden;
}

#screen {
    width: 100%;
    max-width: 760px;
    aspect-ratio: 4 / 3;
    background: #000000;
    border-radius: 10px;
    cursor: default;
    display: block;
    box-shadow: 0 0 20px rgba(0, 255, 102, 0.08);
}

.monitor-control-strip {
    width: 100%;
    margin-top: 14px;
    padding-top: 10px;
    border-top: 1px solid #3a404c;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.bezel-badge-group {
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 12px;
    color: #b0b8c4;
}

.crt-knobs-group {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 11px;
}

.knob-item {
    display: flex;
    align-items: center;
    gap: 5px;
    background: #1b1f26;
    padding: 4px 8px;
    border-radius: 4px;
    border: 1px solid #323844;
}

.knob-item input[type="range"] {
    width: 65px;
    accent-color: var(--accent-green);
    cursor: pointer;
}

.btn-power-switch {
    background: #2b1d1d;
    border: 2px solid #633333;
    color: #ffaaaa;
    font-weight: bold;
    padding: 6px 12px;
    border-radius: 6px;
}

.btn-power-switch.active {
    background: #163826;
    border-color: var(--accent-green);
    color: var(--accent-green);
}

/* ==========================================================================
   Common Buttons, Badges, LEDs, & Inputs
   ========================================================================== */

button {
    background: #21262d;
    color: var(--text-primary);
    border: 1px solid #38414d;
    padding: 7px 13px;
    border-radius: 5px;
    font-family: inherit;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.15s ease;
}

button:hover {
    background: #2c333d;
    border-color: var(--accent-green);
    color: #fff;
}

.btn-accent {
    background: #133926;
    color: var(--accent-green);
    border-color: var(--accent-green);
    font-weight: bold;
}

.btn-accent:hover {
    background: var(--accent-green);
    color: #09130c;
}

.btn-danger {
    background: #3b181b;
    color: #ff7b72;
    border-color: #8c2d33;
}

.btn-danger:hover {
    background: #ff4444;
    color: #fff;
}

.btn-small {
    padding: 4px 9px;
    font-size: 11px;
}

.retro-select, input[type="text"] {
    background: #0d1117;
    color: var(--text-primary);
    border: 1px solid #38414d;
    padding: 7px 10px;
    border-radius: 4px;
    font-family: inherit;
    font-size: 12px;
}

.led {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--led-off);
    display: inline-block;
    vertical-align: middle;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.8);
    transition: background 0.06s, box-shadow 0.06s;
}

.led.active {
    background: var(--led-on, #00ff66);
    box-shadow: 0 0 8px var(--led-on, #00ff66);
}

.badge {
    background: #262f3d;
    color: var(--accent-cyan);
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: bold;
    border: 1px solid #3b495e;
}

/* ==========================================================================
   Tab 4: Custom Card Studio (IDE & Test Harness)
   ========================================================================== */

.studio-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 20px;
}

@media (max-width: 960px) {
    .studio-grid {
        grid-template-columns: 1fr;
    }
}

.studio-panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

#studio-code-editor {
    width: 100%;
    min-height: 410px;
    background: #090c10;
    color: #a5d6ff;
    border: 1px solid #2d3540;
    border-radius: 6px;
    padding: 14px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 13px;
    line-height: 1.45;
    resize: vertical;
}

.harness-led-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    background: #0d1117;
    padding: 12px;
    border-radius: 6px;
    border: 1px solid #282f3a;
}

.harness-led-box {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    background: #161c24;
    padding: 5px 10px;
    border-radius: 4px;
}

/* ==========================================================================
   Tab 5: System Specs & Register Diagnostics
   ========================================================================== */

.reg-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 10px;
}

.reg-box {
    background: #0d1117;
    border: 1px solid #28303d;
    padding: 8px 12px;
    border-radius: 5px;
    display: flex;
    justify-content: space-between;
    font-size: 13px;
}

.reg-box span {
    color: var(--text-muted);
}

.reg-box b {
    color: var(--accent-green);
}

.hex-dump-box {
    background: #090c10;
    color: #7ee787;
    border: 1px solid #28303d;
    padding: 14px;
    border-radius: 6px;
    font-size: 12px;
    line-height: 1.5;
    overflow-x: auto;
    white-space: pre;
}