:root {
    --hud-color: #00ff66; /* Default tech green */
    --hud-glow: rgba(0, 255, 102, 0.5);
    --hud-danger: #ff3333;
    --hud-font: 'Orbitron', sans-serif;
    --ui-font: 'Inter', sans-serif;
    
    --bg-glass: rgba(15, 20, 30, 0.6);
    --border-glass: rgba(255, 255, 255, 0.1);
}

body.theme-airliner {
    --hud-color: #ffffff;
    --hud-glow: rgba(255, 255, 255, 0.3);
}

body.theme-light {
    --hud-color: #ffaa00;
    --hud-glow: rgba(255, 170, 0, 0.3);
}

body, html {
    margin: 0;
    padding: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    background-color: #000;
    font-family: var(--ui-font);
    user-select: none;
}

/* --- 3D CANVAS --- */
#canvas-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

/* --- HUD SECION --- */
#hud {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 5;
    pointer-events: none; /* Let clicks pass through to canvas */
    color: var(--hud-color);
    font-family: var(--hud-font);
    text-shadow: 0 0 5px var(--hud-glow);
    box-sizing: border-box;
    display: none; /* Hidden until started */
}

/* Crosshair */
#crosshair {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100px;
    height: 100px;
}
#crosshair .line { position: absolute; background: var(--hud-color); box-shadow: 0 0 5px var(--hud-glow); }
#crosshair .horizontal { height: 2px; width: 30px; top: 49px; }
#crosshair .left { left: 0; }
#crosshair .right { right: 0; }
#crosshair .vertical { width: 2px; height: 30px; left: 49px; }
#crosshair .top { top: 0; }
#crosshair .circle {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 8px; height: 8px;
    border: 2px solid var(--hud-color);
    border-radius: 50%;
    box-shadow: 0 0 5px var(--hud-glow);
}

/* Pitch Ladder */
#pitch-ladder-container {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 400px;
    height: 600px;
    transform: translate(-50%, -50%);
    overflow: hidden;
    /* We handle rolling via JS transforming the inner #pitch-ladder */
}
#pitch-ladder {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 2000px; /* Long enough to scroll */
    transform-origin: center center;
    /* JS will set translate(-50%, calc(-50% + pitchOffset)) AND rotate(roll) */
}
.pitch-line {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 2px;
    background: var(--hud-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.pitch-line.gap { background: transparent; }
.pitch-line.gap::before, .pitch-line.gap::after {
    content: '';
    display: block;
    width: 40%;
    height: 2px;
    background: var(--hud-color);
}
.pitch-line.horizon {
    width: 800px; /* Very wide */
    background: var(--hud-color);
    height: 3px;
}
.pitch-number {
    position: absolute;
    font-size: 14px;
    font-weight: bold;
}
.pitch-number.left { left: -30px; }
.pitch-number.right { right: -30px; }

/* Tapes (Speed, Alt, Heading) */
.tape-container {
    position: absolute;
    display: flex;
    flex-direction: column;
    align-items: center;
}
.tape-container.left { top: 50%; left: 5%; transform: translateY(-50%); }
.tape-container.right { top: 50%; right: 5%; transform: translateY(-50%); }
.tape-container.top { top: 5%; left: 50%; transform: translateX(-50%); flex-direction: row; }

.tape-label {
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: 2px;
}
.heading-label { margin-bottom: 0; margin-left: 15px; font-size: 18px; }

.tape-window {
    position: relative;
    width: 80px;
    height: 300px;
    border: 2px solid var(--hud-color);
    box-shadow: 0 0 10px var(--hud-glow), inset 0 0 10px var(--hud-glow);
    overflow: hidden;
    /* background: rgba(0,0,0,0.2); Semi-trans backdrop could be added */
}
.heading-window { width: 400px; height: 50px; }

.tape-current {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background: var(--hud-color);
    color: #000;
    padding: 5px 10px;
    font-size: 18px;
    font-weight: bold;
    z-index: 10;
    pointer-events: none;
    border-radius: 4px;
}
.heading-current { top: 100%; transform: translate(-50%, -10px); background: transparent; color: var(--hud-color); font-size: 24px; padding:0; }

.tape-scale {
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    /* JS will translate Y based on value */
}
.tape-scale.horizontal {
    top: 0; left: 50%; width: 2000px; height: 100%;
    /* JS translates X */
}

.tape-mark {
    position: absolute;
    left: 0;
    width: 20px;
    height: 2px;
    background: var(--hud-color);
}
.tape-mark.major { width: 30px; }
.tape-mark-num {
    position: absolute;
    left: 40px;
    top: -8px;
    font-size: 14px;
}
/* For heading */
.heading-mark {
    position: absolute;
    top: 0;
    width: 2px;
    height: 15px;
    background: var(--hud-color);
}
.heading-mark.major { height: 25px; }
.heading-mark-num {
    position: absolute;
    top: 30px;
    transform: translateX(-50%);
    font-size: 14px;
}

/* Telemetry / Info */
#telemetry {
    position: absolute;
    bottom: 5%;
    left: 5%;
    font-size: 16px;
    line-height: 1.5;
}
.highlight {
    font-weight: 700;
    font-size: 18px;
}

/* --- UI OVERLAY (START SCREEN / GLASSMORPHISM) --- */
#ui-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 100;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(10px);
    transition: opacity 0.5s ease;
}
#ui-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.panel {
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: 20px;
    padding: 40px;
    width: 500px;
    color: #fff;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5), inset 0 0 20px rgba(255,255,255,0.05);
}

h1 {
    font-family: var(--hud-font);
    font-size: 32px;
    margin: 0 0 10px 0;
    text-align: center;
    letter-spacing: 2px;
    background: linear-gradient(90deg, #fff, #888);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.subtitle {
    text-align: center;
    color: #aaa;
    margin-bottom: 30px;
    font-size: 14px;
}

.input-group { margin-bottom: 25px; }
label { display: block; font-size: 12px; color: #888; text-transform: uppercase; margin-bottom: 8px;}
.search-box {
    display: flex;
    gap: 10px;
}
input {
    flex: 1;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 8px;
    padding: 12px 15px;
    color: #fff;
    font-size: 16px;
    font-family: var(--ui-font);
    outline: none;
    transition: border 0.3s ease;
}
input:focus { border-color: #00ff66; }
button {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 8px;
    color: #fff;
    padding: 10px 20px;
    cursor: pointer;
    font-family: var(--ui-font);
    font-weight: 600;
    transition: all 0.3s ease;
}
button:hover {
    background: rgba(255,255,255,0.2);
}

.feedback {
    margin-top: 8px;
    font-size: 12px;
    color: #00ff66;
    font-family: var(--hud-font);
    display: none;
}

.quick-select p { font-size: 12px; color: #888; text-transform: uppercase; margin-bottom: 8px; }
.buttons { display: flex; gap: 10px; margin-bottom: 30px; }
.cat-btn { flex: 1; border-radius: 6px; padding: 8px; }
.cat-btn.active {
    background: #fff;
    color: #000;
}

.instructions {
    background: rgba(0,0,0,0.3);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 30px;
}
.instructions h3 { margin: 0 0 10px 0; font-size: 14px; color: #aaa; text-transform: uppercase;}
.instructions ul { margin: 0; padding-left: 20px; color: #fff; font-size: 14px; line-height: 1.6; }
.instructions li strong { color: #00ff66; }

.primary-btn {
    width: 100%;
    padding: 15px;
    font-size: 18px;
    background: linear-gradient(135deg, #00ff66, #00cc55);
    border: none;
    color: #000;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,255,102,0.4);
}
.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 25px rgba(0,255,102,0.6);
}