/* Design System & Root Variables */
:root {
    --bg-color: #05050a;
    --panel-bg: rgba(20, 20, 40, 0.6);
    --accent-color: #00f2ff;
    --accent-glow: rgba(0, 242, 255, 0.4);
    --error-color: #ff3e3e;
    --success-color: #3eff8b;
    --text-primary: #ffffff;
    --text-secondary: #8080a0;
    --card-width: 120px;
    --card-height: 160px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-image: 
        radial-gradient(circle at 50% 50%, #101025 0%, #050510 100%),
        linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
    background-size: 100% 100%, 50px 50px, 50px 50px;
}

/* Header */
header {
    padding: 20px 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(10, 10, 20, 0.8);
    backdrop-filter: blur(15px);
    border-bottom: 1px solid rgba(0, 242, 255, 0.1);
    z-index: 100;
}

.logo {
    font-size: 28px;
    font-weight: 900;
    letter-spacing: 4px;
    background: linear-gradient(135deg, #00f2ff, #7b00ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 10px rgba(0, 242, 255, 0.3));
}

.stats {
    display: flex;
    gap: 40px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.stat-label {
    font-size: 10px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent-color);
    opacity: 0.7;
}

.stat-value {
    font-size: 24px;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

/* Game Layout */
#game-container {
    flex: 1;
    position: relative;
    display: flex;
    justify-content: space-between;
    padding: 40px 8%;
}

.source-zone {
    width: 200px;
    border-right: 1px dashed rgba(255,255,255,0.05);
}

.target-zone {
    width: 320px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 25px;
}

/* The X-Ray Machine */
.xray-machine {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -40%);
    width: 300px;
    height: 70%;
    background: linear-gradient(135deg, #151525 0%, #0a0a15 100%);
    border-radius: 40px;
    border: 3px solid rgba(255,255,255,0.05);
    box-shadow: 
        0 0 100px rgba(0,0,0,0.8),
        inset 0 0 50px rgba(0, 242, 255, 0.05);
    display: flex;
    flex-direction: column;
    padding: 20px;
}

.xray-machine::before {
    content: 'X-RAY SCANNER v2.0';
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 10px;
    letter-spacing: 3px;
    color: var(--accent-color);
    opacity: 0.5;
}

.xray-window {
    flex: 1;
    background: rgba(0, 5, 10, 0.9);
    border-radius: 20px;
    border: 1px solid rgba(0, 242, 255, 0.2);
    position: relative;
    overflow: hidden;
    box-shadow: inset 0 0 30px rgba(0, 242, 255, 0.2);
}

.xray-beam {
    position: absolute;
    width: 100%;
    height: 10px;
    background: var(--accent-color);
    box-shadow: 0 0 20px var(--accent-color);
    opacity: 0.4;
    top: 50%;
    transform: translateY(-50%);
    animation: scanVertical 4s infinite ease-in-out;
}

@keyframes scanVertical {
    0%, 100% { top: 10%; }
    50% { top: 90%; }
}

/* Cards */
.card {
    width: var(--card-width);
    height: var(--card-height);
    background: linear-gradient(135deg, #2a2a40 0%, #1a1a2a 100%);
    border-radius: 16px;
    border: 1px solid rgba(255,255,255,0.1);
    display: flex;
    justify-content: center;
    align-items: center;
    position: fixed; /* For manual dragging */
    z-index: 10;
    cursor: grab;
    user-select: none;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.card:active {
    cursor: grabbing;
}

.card .hidden-content {
    display: none;
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    color: var(--accent-color);
    text-shadow: 0 0 15px var(--accent-glow);
}

.card .visible-content {
    font-size: 50px;
    color: rgba(255,255,255,0.1);
    font-weight: 900;
}

.card-revealed {
    background: transparent !important;
    border: 2px solid var(--accent-color) !important;
    box-shadow: 0 0 40px var(--accent-glow) !important;
}

.card-revealed .visible-content {
    display: none;
}

.card-revealed .hidden-content {
    display: block;
}

/* Targets */
.target-slot {
    height: 160px;
    background: var(--panel-bg);
    border-radius: 20px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.target-slot::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, rgba(0,242,255,0.05) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.3s;
}

.target-slot:hover {
    transform: translateX(-10px);
    background: rgba(30, 30, 60, 0.8);
    border-color: rgba(0, 242, 255, 0.3);
}

.target-slot:hover::after {
    opacity: 1;
}

.fraction-model {
    width: 100px;
    height: 100px;
    filter: drop-shadow(0 0 10px rgba(0, 242, 255, 0.2));
}

/* Feedback */
.feedback {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 80px;
    font-weight: 900;
    letter-spacing: 5px;
    pointer-events: none;
    opacity: 0;
    z-index: 2000;
    text-shadow: 0 0 30px rgba(0,0,0,0.5);
}

.feedback.correct {
    color: var(--success-color);
    animation: feedbackPop 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.feedback.wrong {
    color: var(--error-color);
    animation: feedbackPop 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes feedbackPop {
    0% { transform: translate(-50%, -50%) scale(0.5); opacity: 0; }
    30% { transform: translate(-50%, -50%) scale(1.1); opacity: 1; }
    70% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(1.2); opacity: 0; }
}