/* Custom variables for Cyberpunk Theme */
:root {
    --bg-dark: #07070d;
    --bg-card: rgba(16, 16, 32, 0.65);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(0, 240, 255, 0.15);
    
    --color-p1: #00f0ff;
    --color-p1-dark: #006b99;
    --color-p1-glow: rgba(0, 240, 255, 0.4);
    
    --color-p2: #ff007f;
    --color-p2-dark: #99004d;
    --color-p2-glow: rgba(255, 0, 127, 0.4);

    --color-neutral: #a0a0c0;
    --color-success: #39ff14;
    --color-success-glow: rgba(57, 255, 20, 0.4);
    
    --font-orbitron: 'Orbitron', sans-serif;
    --font-inter: 'Inter', sans-serif;
    
    --board-size: 400px;
    --cell-size: 90px;
}

/* Reset & Base Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-dark);
    color: #e2e2ee;
    font-family: var(--font-inter);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow-x: hidden;
}

/* Cyberpunk Background Glow */
.cyber-bg-glow {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: -1;
    background: 
        radial-gradient(circle at 10% 20%, rgba(0, 114, 255, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(255, 0, 127, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 50% 50%, rgba(16, 16, 32, 0.5) 0%, #07070d 100%);
    pointer-events: none;
}

/* Glassmorphism Panel Card */
.glassmorphism {
    background: var(--bg-card);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.glassmorphism:hover {
    border-color: rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.5), 0 0 15px rgba(255, 255, 255, 0.02);
}

/* Layout Container */
.app-container {
    width: 100%;
    max-width: 1200px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    min-height: 95vh;
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: 5px;
}

.app-header h1 {
    font-family: var(--font-orbitron);
    font-size: 2.2rem;
    font-weight: 900;
    letter-spacing: 4px;
    margin-bottom: 4px;
}

.glow-text {
    background: linear-gradient(90deg, var(--color-p1), var(--color-p2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 10px rgba(0, 240, 255, 0.3));
}

.subtitle {
    font-family: var(--font-orbitron);
    font-size: 0.8rem;
    letter-spacing: 6px;
    color: var(--color-neutral);
    text-transform: uppercase;
}

/* Main Grid Layout */
.game-layout {
    display: grid;
    grid-template-columns: 280px 1fr 280px;
    gap: 24px;
    align-items: start;
    flex-grow: 1;
}

/* Side Panels */
.side-panel {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.panel-card {
    padding: 16px;
}

.panel-title {
    font-family: var(--font-orbitron);
    font-size: 0.9rem;
    letter-spacing: 2px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: #e2e2ee;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 8px;
}

/* Button & Control Groups */
.control-group, .difficulty-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.mode-btn, .diff-btn, .control-btn, .reset-btn, .rules-modal-trigger {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: #a0a0c0;
    padding: 10px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-family: var(--font-inter);
    font-weight: 500;
    font-size: 0.9rem;
    text-align: left;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.2s ease;
}

.mode-btn:hover, .diff-btn:hover, .control-btn:hover:not(:disabled), .rules-modal-trigger:hover {
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    border-color: rgba(255, 255, 255, 0.2);
}

.mode-btn.active {
    background: rgba(0, 240, 255, 0.1);
    border-color: var(--color-p1);
    color: var(--color-p1);
    box-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
}

#btn-pvp.active {
    background: rgba(0, 240, 255, 0.1);
    border-color: var(--color-p1);
    color: var(--color-p1);
}

#btn-pvai.active {
    background: rgba(150, 0, 255, 0.1);
    border-color: #a855f7;
    color: #c084fc;
    box-shadow: 0 0 10px rgba(168, 85, 247, 0.2);
}

#btn-aivai.active {
    background: rgba(255, 0, 127, 0.1);
    border-color: var(--color-p2);
    color: var(--color-p2);
    box-shadow: 0 0 10px rgba(255, 0, 127, 0.2);
}

/* Difficulty Button Layout */
.difficulty-group {
    flex-direction: row;
}

.diff-btn {
    flex: 1;
    justify-content: center;
    padding: 8px;
    font-size: 0.85rem;
}

.diff-btn.active {
    background: rgba(255, 255, 255, 0.1);
    border-color: #fff;
    color: #fff;
    font-weight: 700;
}

/* Game Status Card */
.game-status-card {
    min-height: 180px;
    display: flex;
    flex-direction: column;
}

.turn-box {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px;
    border-radius: 8px;
    font-family: var(--font-orbitron);
    font-weight: 700;
    font-size: 0.95rem;
    margin-bottom: 12px;
    border-left: 4px solid var(--color-neutral);
    background: rgba(255, 255, 255, 0.02);
    transition: all 0.3s ease;
}

.turn-box.player1-turn {
    border-left-color: var(--color-p1);
    background: rgba(0, 240, 255, 0.05);
    color: var(--color-p1);
    text-shadow: 0 0 5px var(--color-p1-glow);
}

.turn-box.player2-turn {
    border-left-color: var(--color-p2);
    background: rgba(255, 0, 127, 0.05);
    color: var(--color-p2);
    text-shadow: 0 0 5px var(--color-p2-glow);
}

.turn-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--color-neutral);
    box-shadow: 0 0 8px var(--color-neutral);
}

.player1-turn .turn-dot {
    background-color: var(--color-p1);
    box-shadow: 0 0 10px var(--color-p1);
    animation: pulse 1.5s infinite;
}

.player2-turn .turn-dot {
    background-color: var(--color-p2);
    box-shadow: 0 0 10px var(--color-p2);
    animation: pulse 1.5s infinite;
}

.status-stats {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    margin-top: auto;
}

.stat-item {
    flex: 1;
    background: rgba(255, 255, 255, 0.02);
    padding: 8px;
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.03);
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--color-neutral);
    margin-bottom: 2px;
}

.stat-value {
    font-family: var(--font-orbitron);
    font-weight: 700;
    font-size: 1rem;
    color: #fff;
}

.setup-instruction-box {
    margin-top: 12px;
    background: rgba(255, 255, 255, 0.02);
    padding: 10px;
    border-radius: 8px;
    border: 1px dashed rgba(255, 255, 255, 0.1);
    font-size: 0.8rem;
    line-height: 1.4;
    color: #b0b0c8;
}

.setup-instruction-box p {
    animation: textGlowPulse 2s infinite alternate;
}

/* Center Panel - Board */
.board-container {
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 800px; /* 3D effect perspective */
}

.board-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    transition: transform 0.8s cubic-bezier(0.19, 1, 0.22, 1);
}

.game-board {
    width: var(--board-size);
    height: var(--board-size);
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    grid-template-rows: repeat(5, 1fr);
    gap: 10px;
    padding: 12px;
    background: rgba(10, 10, 20, 0.8);
    border: 2px solid var(--border-glow);
    border-radius: 16px;
    box-shadow: 
        0 15px 35px rgba(0, 0, 0, 0.6),
        0 0 30px rgba(0, 240, 255, 0.05),
        inset 0 0 20px rgba(255, 255, 255, 0.02);
    transform: rotateX(10deg); /* Tilt board slightly for 3D stack depth */
    transform-style: preserve-3d;
}

/* Grid Cell */
.cell {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    border-radius: 8px;
    position: relative;
    cursor: pointer;
    transition: all 0.25s ease;
    transform-style: preserve-3d;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
}

.cell::before {
    content: '';
    position: absolute;
    top: 4px;
    left: 4px;
    right: 4px;
    bottom: 4px;
    border: 1px dashed rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    pointer-events: none;
}

.cell:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.12);
}

/* Goal Highlight indicators on cells */
.cell.p1-goal-line::after, .cell.p2-goal-line::after {
    content: '';
    position: absolute;
    height: 2px;
    left: 10px;
    right: 10px;
    pointer-events: none;
    opacity: 0.3;
}

.cell.p1-goal-line::after {
    top: 4px;
    background: var(--color-p2);
    box-shadow: 0 0 5px var(--color-p2);
}

.cell.p2-goal-line::after {
    bottom: 4px;
    background: var(--color-p1);
    box-shadow: 0 0 5px var(--color-p1);
}

/* Stacks count text on cells (if hidden behind, shows helper badge) */
.stack-badge {
    position: absolute;
    top: 4px;
    right: 6px;
    background: rgba(0, 0, 0, 0.6);
    color: var(--color-neutral);
    font-family: var(--font-orbitron);
    font-size: 0.65rem;
    font-weight: 700;
    padding: 1px 4px;
    border-radius: 4px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    pointer-events: none;
    z-index: 100;
    opacity: 0.6;
    transition: opacity 0.2s ease;
}

.cell:hover .stack-badge {
    opacity: 1;
}

/* Legal Move Highlights */
.cell.legal-target {
    border-color: var(--color-success);
    box-shadow: 
        inset 0 0 10px rgba(57, 255, 20, 0.15),
        0 0 10px rgba(57, 255, 20, 0.1);
    animation: targetPulse 1.5s infinite alternate;
}

.cell.legal-target::before {
    border-color: var(--color-success);
    opacity: 0.4;
}

.cell.legal-target:hover {
    background: rgba(57, 255, 20, 0.08);
    box-shadow: 
        inset 0 0 15px rgba(57, 255, 20, 0.3),
        0 0 15px rgba(57, 255, 20, 0.3);
}

/* 3D Stackable Cylindrical Pieces */
.piece {
    position: absolute;
    left: 50%;
    width: 58px;
    height: 24px;
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.2), box-shadow 0.3s ease;
    transform-style: preserve-3d;
}

/* Absolute offsets for layers in default stacked state */
.piece.layer-0 {
    bottom: 12px;
    z-index: 10;
    transform: translate(-50%, 0);
}

.piece.layer-1 {
    bottom: 24px;
    z-index: 20;
    transform: translate(-50%, 0);
}

.piece.layer-2 {
    bottom: 36px;
    z-index: 30;
    transform: translate(-50%, 0);
}

/* Spring Expansion on Hover: Cells expand stacks slightly vertically when hovered */
.cell:hover .piece.layer-0 {
    transform: translate(-50%, 4px);
}

.cell:hover .piece.layer-1 {
    transform: translate(-50%, -8px);
}

.cell:hover .piece.layer-2 {
    transform: translate(-50%, -20px);
}

/* Piece visual look: 3D cylinders */
.piece.p1 {
    background: radial-gradient(circle at 50% 30%, #5ce1e6 0%, var(--color-p1) 50%, #004d61 100%);
    border-bottom: 5px solid #005a73;
    box-shadow: 
        0 4px 6px rgba(0, 0, 0, 0.4),
        0 0 8px rgba(0, 240, 255, 0.2),
        inset 0 1px 2px rgba(255, 255, 255, 0.4);
}

.piece.p2 {
    background: radial-gradient(circle at 50% 30%, #ff66a3 0%, var(--color-p2) 50%, #610030 100%);
    border-bottom: 5px solid #730039;
    box-shadow: 
        0 4px 6px rgba(0, 0, 0, 0.4),
        0 0 8px rgba(255, 0, 127, 0.2),
        inset 0 1px 2px rgba(255, 255, 255, 0.4);
}

/* Highlight Selected Piece (Pulsing glowing ring + lift) */
.piece.selected {
    box-shadow: 
        0 0 15px 5px #fff,
        inset 0 1px 2px rgba(255, 255, 255, 0.6);
    animation: selectionLift 1.5s infinite alternate;
}

.piece.p1.selected {
    box-shadow: 
        0 0 18px rgba(0, 240, 255, 0.8),
        0 10px 15px rgba(0, 0, 0, 0.5),
        inset 0 1px 2px rgba(255, 255, 255, 0.6);
}

.piece.p2.selected {
    box-shadow: 
        0 0 18px rgba(255, 0, 127, 0.8),
        0 10px 15px rgba(0, 0, 0, 0.5),
        inset 0 1px 2px rgba(255, 255, 255, 0.6);
}

/* Disable top pieces selection or animations during AI turns */
.piece.unselectable {
    cursor: default !important;
}

/* Right Panel: Controls Action Grid */
.action-panel {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.action-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.control-btn {
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 6px;
    padding: 12px;
    text-align: center;
    font-size: 0.75rem;
}

.control-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.svg-icon {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

.reset-btn {
    background: linear-gradient(135deg, rgba(255, 0, 127, 0.15) 0%, rgba(150, 0, 255, 0.15) 100%);
    border: 1px solid rgba(255, 0, 127, 0.3);
    color: #ffa6c9;
    font-family: var(--font-orbitron);
    font-weight: 700;
    letter-spacing: 1px;
    width: 100%;
    padding: 12px;
    justify-content: center;
}

.reset-btn:hover {
    background: linear-gradient(135deg, rgba(255, 0, 127, 0.3) 0%, rgba(150, 0, 255, 0.3) 100%);
    border-color: var(--color-p2);
    box-shadow: 0 0 10px rgba(255, 0, 127, 0.3);
}

/* Move Logs */
.log-panel {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    max-height: 220px;
}

.log-list {
    margin-top: 8px;
    overflow-y: auto;
    font-size: 0.8rem;
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex-grow: 1;
    padding-right: 6px;
}

.log-list::-webkit-scrollbar {
    width: 4px;
}

.log-list::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 2px;
}

.log-empty-msg {
    color: var(--color-neutral);
    text-align: center;
    font-style: italic;
    margin-top: 20px;
}

.log-item {
    display: flex;
    justify-content: space-between;
    padding: 6px 10px;
    background: rgba(255, 255, 255, 0.01);
    border-left: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

.log-item.player1 {
    border-left-color: var(--color-p1);
    background: rgba(0, 240, 255, 0.02);
}

.log-item.player2 {
    border-left-color: var(--color-p2);
    background: rgba(255, 0, 127, 0.02);
}

.log-num {
    font-family: var(--font-orbitron);
    color: var(--color-neutral);
    font-size: 0.75rem;
}

.log-move {
    font-weight: 500;
}

.rules-modal-trigger {
    border-color: rgba(255, 255, 255, 0.08);
    justify-content: center;
    font-weight: 500;
    padding: 12px;
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(8px);
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.modal-content {
    background: #0f0f1d;
    max-width: 600px;
    width: 100%;
    border: 1px solid var(--border-glow);
    border-radius: 16px;
    padding: 24px;
    position: relative;
    max-height: 85vh;
    overflow-y: auto;
}

.close-btn {
    position: absolute;
    right: 20px;
    top: 16px;
    font-size: 24px;
    color: var(--color-neutral);
    cursor: pointer;
    transition: color 0.2s ease;
}

.close-btn:hover {
    color: #fff;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 900;
    letter-spacing: 2px;
    color: var(--color-p1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 10px;
    margin-bottom: 16px;
}

.rules-body {
    display: flex;
    flex-direction: column;
    gap: 16px;
    font-size: 0.9rem;
    line-height: 1.6;
    color: #c8c8dd;
}

.rules-body h3 {
    font-family: var(--font-orbitron);
    font-size: 1rem;
    color: #fff;
    margin-top: 8px;
    border-left: 3px solid var(--color-p2);
    padding-left: 8px;
}

.rules-body ul, .rules-body ol {
    padding-left: 20px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.rules-demo-grid {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: 12px;
    border-radius: 8px;
}

.modal-footer {
    margin-top: 24px;
    display: flex;
    justify-content: flex-end;
}

.modal-action-btn {
    background: var(--color-p1);
    border: none;
    color: #07070d;
    font-family: var(--font-orbitron);
    font-weight: 900;
    padding: 10px 24px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.3);
}

.modal-action-btn:hover {
    background: #fff;
    box-shadow: 0 0 20px #fff;
}

/* Victory Gameover Screen Overlay */
.gameover-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(5, 5, 10, 0.85);
    backdrop-filter: blur(12px);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    transition: opacity 0.5s ease;
}

.gameover-box {
    text-align: center;
    background: rgba(15, 15, 30, 0.9);
    border: 2px solid var(--color-p1);
    max-width: 450px;
    width: 100%;
    border-radius: 20px;
    padding: 40px 30px;
    box-shadow: 
        0 20px 50px rgba(0, 0, 0, 0.8),
        0 0 30px rgba(0, 240, 255, 0.2);
    animation: zoomIn 0.4s cubic-bezier(0.18, 0.89, 0.32, 1.28);
}

.victory-title {
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: 6px;
    background: linear-gradient(90deg, var(--color-p1), var(--color-p2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 12px;
}

.winner-announcement {
    font-size: 1.3rem;
    font-weight: 500;
    color: #fff;
    margin-bottom: 24px;
    letter-spacing: 1px;
}

.victory-stats {
    display: flex;
    justify-content: space-around;
    background: rgba(255, 255, 255, 0.02);
    padding: 16px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    margin-bottom: 30px;
}

.v-stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.v-label {
    font-size: 0.75rem;
    color: var(--color-neutral);
}

.v-value, #v-turns, #v-cause {
    font-family: var(--font-orbitron);
    font-weight: 700;
    font-size: 1.1rem;
    color: #fff;
}

.restart-action-btn {
    background: linear-gradient(90deg, var(--color-p1), var(--color-p2));
    border: none;
    color: #fff;
    padding: 14px 40px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 900;
    letter-spacing: 2px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
}

.restart-action-btn:hover {
    box-shadow: 
        0 0 30px rgba(0, 240, 255, 0.5),
        0 0 10px rgba(255, 0, 127, 0.5);
    transform: scale(1.05);
}

/* Footer styling */
.app-footer {
    text-align: center;
    font-size: 0.7rem;
    letter-spacing: 1px;
    color: rgba(255, 255, 255, 0.2);
    margin-top: auto;
    padding-top: 20px;
}

/* Animations & Helpers */
.hidden {
    display: none !important;
}

.font-orbitron {
    font-family: var(--font-orbitron);
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 0.6; }
    50% { transform: scale(1.25); opacity: 1; }
    100% { transform: scale(1); opacity: 0.6; }
}

@keyframes targetPulse {
    0% { border-color: rgba(57, 255, 20, 0.4); box-shadow: inset 0 0 8px rgba(57, 255, 20, 0.1); }
    100% { border-color: var(--color-success); box-shadow: inset 0 0 18px rgba(57, 255, 20, 0.35), 0 0 8px rgba(57, 255, 20, 0.15); }
}

@keyframes textGlowPulse {
    from { text-shadow: 0 0 2px rgba(255, 255, 255, 0.1); }
    to { text-shadow: 0 0 10px rgba(255, 255, 255, 0.3); }
}

@keyframes selectionLift {
    0% { transform: translate(-50%, var(--lift-start)) scale(1.0); }
    100% { transform: translate(-50%, var(--lift-end)) scale(1.06); }
}

@keyframes zoomIn {
    from { transform: scale(0.85); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

/* Board rotation utilities */
.board-rotated {
    transform: rotate(180deg);
}

/* If board is rotated, we want pieces to stay readable/vertical from player's POV (optional), 
   but for abstraction we flip piece orientation to counter rotation if desired. 
   Instead we rotate the entire board-rotation-wrapper */
.board-rotated .piece {
    /* Keep stack visualization upside down or rotate them back. 
       Usually it is fine to let the whole board rotate 180 degrees so the other player sees it from their perspective! */
}

/* Responsive Breakpoints */
@media (max-width: 1024px) {
    .game-layout {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .side-panel {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .panel-card {
        flex: 1 1 240px;
    }
    
    .left-panel {
        order: 1;
    }
    
    .board-container {
        order: 2;
        padding: 10px 0;
    }
    
    .right-panel {
        order: 3;
    }
    
    .log-panel {
        max-height: 150px;
    }
}

@media (max-width: 480px) {
    :root {
        --board-size: 320px;
        --cell-size: 72px;
    }
    
    .piece {
        width: 46px;
        height: 18px;
    }
    
    .app-header h1 {
        font-size: 1.6rem;
    }
    
    .side-panel {
        flex-direction: column;
    }
    
    .panel-card {
        flex: 1 1 auto;
    }
}

/* ==========================================================================
   PREMIUM / STRIPE STYLES
   ========================================================================== */

/* Premium Panel Card */
.premium-card {
    border: 1px solid rgba(255, 215, 0, 0.3) !important; /* Gold border glow */
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.1);
}

.premium-card .panel-title {
    color: #ffd700 !important; /* Gold */
    text-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
}

#premium-status-indicator {
    background: rgba(255, 215, 0, 0.1);
    border: 1px solid rgba(255, 215, 0, 0.2);
    border-radius: 8px;
    padding: 8px 12px;
    text-align: center;
    font-weight: bold;
    color: #ffd700;
    margin: 8px 0;
}

#premium-status-indicator.premium-active {
    background: rgba(0, 255, 127, 0.1);
    border: 1px solid rgba(0, 255, 127, 0.2);
    color: #00ff7f; /* Spring green */
    text-shadow: 0 0 8px rgba(0, 255, 127, 0.4);
}

.premium-action-btn {
    width: 100%;
    background: linear-gradient(135deg, #ffd700, #ffa500);
    border: none;
    color: #07070d;
    font-weight: bold;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    margin-top: 12px;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.2);
    transition: all 0.3s ease;
}

.premium-action-btn:hover {
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
    transform: translateY(-1px);
}

/* Premium Modal styling */
.premium-modal-content {
    max-width: 450px !important;
    border: 2px solid #ffd700 !important;
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.3) !important;
}

.premium-body {
    display: flex;
    flex-direction: column;
    gap: 16px;
    font-size: 0.95rem;
    line-height: 1.6;
    color: #c8c8dd;
}

.premium-highlight-box {
    background: rgba(255, 215, 0, 0.05);
    border: 1px dashed rgba(255, 215, 0, 0.3);
    border-radius: 8px;
    padding: 16px;
    text-align: center;
    margin-bottom: 8px;
}

.premium-status-desc {
    color: #fff;
    font-size: 0.95rem;
    margin: 0;
}

.premium-price {
    font-size: 1.25rem;
    font-weight: bold;
    margin: 8px 0 0 0;
    color: #fff;
}

.premium-price .price-val {
    color: #ffd700;
    font-size: 1.6rem;
    text-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
}

.premium-features-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 12px;
}

.feature-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    line-height: 1;
}

.feature-text strong {
    color: #fff;
    font-size: 0.95rem;
}

.feature-text p {
    color: #a8a8bb;
    font-size: 0.85rem;
    margin-top: 4px;
}

.premium-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.checkout-btn {
    width: 100%;
    padding: 14px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    font-family: var(--font-orbitron);
}

.stripe-btn {
    background: #6772e5; /* Stripe indigo */
    color: white;
    border: none;
    box-shadow: 0 0 15px rgba(103, 114, 229, 0.4);
}

.stripe-btn:hover:not(:disabled) {
    background: #7795f8;
    box-shadow: 0 0 20px rgba(103, 114, 229, 0.6);
}

.stripe-btn:disabled {
    background: #4f566b;
    color: #a8a8bb;
    cursor: not-allowed;
    box-shadow: none;
}

.mock-container {
    margin-top: 8px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 12px;
}

.mock-desc {
    font-size: 0.75rem;
    color: #a8a8bb;
    margin-bottom: 6px;
    text-align: center;
}

.mock-btn {
    background: rgba(255, 255, 255, 0.05);
    color: #a8a8bb;
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 10px;
    font-size: 0.85rem;
}

.mock-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-color: rgba(255, 255, 255, 0.2);
}