:root {
    --bg-color: #0d1117;
    --board-bg: #161b22;
    --cell-bg: rgba(238, 228, 218, 0.08);
    --text-main: #f0f6fc;
    --text-dim: #8b949e;
    --accent: #238636;
    --accent-hover: #2ea043;
    --card-bg: #21262d;
    --tile-radius: 6px;
    --transition-speed: 150ms;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-touch-callout: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: 'Inter', 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    /* 원근감(3D Perspective) 제거하여 플랫한 느낌 구현 */
    perspective: none;
    overflow: visible; /* 전체 페이지 스크롤 방지 */
}

/* 게임 컨테이너 */
.game-container {
    padding: 20px;
    max-width: 500px;
    width: 100%;
    position: relative;
    z-index: 10;
}

/* 배경 애니메이션 Layer */
.sky-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
    background: radial-gradient(circle at 50% 10%, #1b263b 0%, #0d1117 70%);
}

.zeppelin {
    position: absolute;
    top: 60px;
    left: -320px; /* 더 넓어진 너비를 고려하여 시작 위치 조정 */
    width: 300px;
    height: 67px;
    background-image: url('resource/airplane/airplane.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    filter: drop-shadow(0 10px 15px rgba(0,0,0,0.3));
    animation: zeppelinMove 40s linear infinite;
    z-index: 1;
}

.zeppelin-logo {
    display: none; /* 비행기 이미지로 대체되므로 텍스트 숨김 */
}

@keyframes zeppelinMove {
    0% { transform: translateX(0) translateY(0); }
    50% { transform: translateX(calc(100vw + 300px)) translateY(20px); }
    100% { transform: translateX(calc(100vw + 300px)) translateY(0); }
}

/* 헤더 & 점수 */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.logo {
    font-family: 'Outfit', sans-serif;
    font-weight: 800;
    font-size: 2rem;
    color: var(--text-main);
    line-height: 1;
}

.logo span {
    color: var(--accent);
}

.subtitle {
    font-size: 0.9rem;
    color: var(--text-dim);
}

.scores-container {
    display: flex;
    gap: 10px;
}

.score-box {
    background: var(--card-bg);
    padding: 8px 15px;
    border-radius: 8px;
    text-align: center;
    min-width: 80px;
    border: 1px solid rgba(255,255,255,0.05);
    transition: transform 0.2s ease;
}

.score-box:active {
    transform: scale(0.95);
}

.score-box.highlight {
    border-color: rgba(35, 134, 54, 0.3);
}

.score-box .label {
    font-size: 0.65rem;
    font-weight: 700;
    color: var(--text-dim);
    margin-bottom: 2px;
}

#score, #best-score {
    font-size: 1.2rem;
    font-weight: 800;
    font-family: 'Outfit', sans-serif;
}

/* 베스트 스코어 초기화 클릭이 가능하도록 인터랙션 추가 */
.score-box.highlight {
    cursor: pointer;
    transition: all 0.2s ease;
}

.score-box.highlight:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
}

.score-box.highlight {
    position: relative;
    border-color: rgba(255, 215, 0, 0.4);
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.1);
}

.best-score-update {
    animation: bestPulse 0.8s ease-out;
    border-color: #ffd700 !important;
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.8), inset 0 0 15px rgba(255, 215, 0, 0.4) !important;
}

@keyframes bestPulse {
    0% { transform: scale(1); }
    30% { transform: scale(1.15); filter: brightness(1.5); }
    100% { transform: scale(1); }
}

.score-box .label {
    display: flex;
    align-items: center;
    justify-content: center;
}

.crown-icon {
    position: absolute;
    top: -16px;
    left: 50%;
    transform: translateX(-50%) rotate(-15deg);
    color: #ffd700;
    filter: drop-shadow(0 0 8px rgba(255, 215, 0, 0.7));
    z-index: 5;
    animation: crownFloat 3s ease-in-out infinite;
}

@keyframes crownFloat {
    0%, 100% { transform: translateX(-50%) rotate(-15deg) translateY(0); }
    50% { transform: translateX(-50%) rotate(-12deg) translateY(-4px); }
}

/* 게임 인트로 (버튼) */
.game-intro {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    gap: 20px;
}

button {
    cursor: pointer;
    border: none;
    border-radius: 6px;
    font-weight: 700;
    transition: all 0.2s ease;
}

#retry-button {
    background-color: var(--accent);
    color: white;
    padding: 10px 25px;
    font-size: 1rem;
    box-shadow: 0 4px 0 #1b6529;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

#restart-button {
    background-color: var(--accent);
    color: white;
    width: 120px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 0 #1b6529;
}

#retry-button:active, #restart-button:active {
    box-shadow: 0 0 0 #1b6529;
    transform: translateY(4px);
}

/* 커스텀 툴팁 (글래스모피즘) */
[data-tooltip] {
    position: relative;
    cursor: pointer;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    color: white;
    font-size: 0.8rem;
    white-space: nowrap;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    z-index: 1000;
}

[data-tooltip]:hover::after {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.tooltip-wrapper {
    display: inline-flex;
    position: relative;
}

button:disabled {
    pointer-events: none;
}

.controls-container {
    display: flex;
    gap: 8px;
}

.level-badge {
    background: #161b22;
    color: #ffd700;
    padding: 0 12px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.9rem;
    border: 1px solid rgba(255, 215, 0, 0.3);
    font-family: 'Outfit', sans-serif;
    min-width: 60px;
    box-shadow: inset 0 0 10px rgba(255, 215, 0, 0.05);
}

.level-up {
    animation: levelPop 0.5s ease-out;
}

@keyframes levelPop {
    0% { transform: scale(1); border-color: #ffd700; box-shadow: 0 0 15px #ffd700; }
    50% { transform: scale(1.2); border-color: #ffffff; box-shadow: 0 0 25px #ffffff; }
    100% { transform: scale(1); border-color: rgba(255, 215, 0, 0.3); }
}

.control-btn {
    background: var(--card-bg);
    color: var(--text-main);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255,255,255,0.1);
}

.control-btn.gold {
    background: #1a1e23;
    padding: 2px;
    border: 2px solid #ffd700;
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.3);
    overflow: hidden;
    position: relative;
}

.joker-btn-img {
    width: 100%;
    height: 100%;
    background-image: url('resource/building/18.png');
    background-size: cover;
    background-position: center;
    border-radius: 4px;
}

.count-badge {
    position: absolute;
    bottom: 2px;
    right: 2px;
    background: #ffd700;
    color: #000;
    font-size: 10px;
    font-weight: 900;
    padding: 1px 4px;
    border-radius: 10px;
    line-height: 1;
}

.control-btn.gold:disabled {
    filter: grayscale(1);
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}

.control-btn.gold:hover:not(:disabled) {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 0 25px rgba(255, 215, 0, 0.6);
}

.control-btn:hover {
    background: #30363d;
    transform: translateY(-2px);
}

#share-button {
    background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(26, 115, 232, 0.3);
}

#share-button:hover {
    background: linear-gradient(135deg, #1b7cf6 0%, #1565c0 100%);
    box-shadow: 0 6px 20px rgba(26, 115, 232, 0.5);
    transform: translateY(-2px) scale(1.05);
}

.control-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent-hover);
}

.tile-container.hide-values .tile-value {
    display: none;
}

.hidden {
    display: none !important;
}

/* 게임 보드 */
.game-board-wrapper {
    position: relative;
    width: 420px;
    height: 420px;
    margin: 50px auto;
    perspective: 1200px; /* 3D 효과를 위한 원근감 추가 */
}

.game-board {
    position: relative;
    padding: 15px;
    background: linear-gradient(145deg, #1e242c, #161b22);
    border-radius: 12px;
    height: 100%;
    touch-action: none;
    box-shadow: 
        0 20px 50px rgba(0,0,0,0.6),
        0 0 0 1px rgba(255,255,255,0.05),
        -5px 15px 0px rgba(0,0,0,0.2); /* 3D 입체감을 위한 그림자 */
    transform-style: preserve-3d;
    transform: rotateX(25deg) rotateZ(-5deg); /* 2048 (New)_02 버전의 정석 각도 */
    transition: transform 0.5s ease;
    
    /* 보드 두께 효과 (Layered shadows) */
    box-shadow: 
        1px 1px 0px #0b0e12,
        2px 2px 0px #0b0e12,
        3px 3px 0px #0b0e12,
        4px 4px 0px #0b0e12,
        5px 5px 0px #0b0e12,
        6px 6px 15px rgba(0,0,0,0.8),
        0 20px 50px rgba(0,0,0,0.6);
}

.game-board:hover {
    transform: rotateX(20deg) rotateZ(-2deg); /* 마우스 오버 시 가벼운 움직임 */
}

/* 보드 하단 그림자 (바닥 효과) */
.game-board::before {
    content: '';
    position: absolute;
    top: 10%;
    left: 10%;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.4);
    filter: blur(40px);
    transform: translateZ(-50px);
    z-index: -1;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 15px;
    width: 100%;
    height: 100%;
    transform: translateZ(10px); /* 그리드 배경을 살짝 띄움 */
}

.grid-cell {
    background: var(--cell-bg);
    border-radius: var(--tile-radius);
    box-shadow: inset 2px 2px 5px rgba(0,0,0,0.3);
}

/* 타일 레이어 */
.tile-container {
    position: absolute;
    top: 15px;
    left: 15px;
    right: 15px;
    bottom: 15px;
    z-index: 10;
    transform-style: preserve-3d;
}

.tile {
    position: absolute;
    width: calc((100% - 45px) / 4);
    height: calc((100% - 45px) / 4);
    border-radius: var(--tile-radius);
    /* 슬라이딩 효과 강화: cubic-bezier 로 완급 조절 */
    transition: left 0.15s cubic-bezier(0.25, 1, 0.5, 1), 
                top 0.15s cubic-bezier(0.25, 1, 0.5, 1), 
                transform var(--transition-speed) ease-in-out;
    transition-property: left, top, transform;
    z-index: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: transparent;
    
    /* 정확한 위치 계산 (JS에서 --r, --c 변수 주입) */
    --tile-size: calc((100% - 45px) / 4);
    --gap: 15px;
    top: calc(var(--r) * (var(--tile-size) + var(--gap)));
    left: calc(var(--c) * (var(--tile-size) + var(--gap)));
    
    transform: translateZ(4px); /* 보드판에 밀착되면서도 입체감 유지 */
    transform-style: preserve-3d;
}

/* 건물 카드 디자인: 다이아몬드(아이소메트릭) 형태 */
.tile-inner {
    width: 100%;
    height: 100%;
    background-color: var(--board-bg);
    border-radius: var(--tile-radius); /* 기존 설정값 사용 */
    box-shadow: 0 4px 15px rgba(0,0,0,0.4);
    
    transform: none; 
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
    border: 2px solid rgba(255,255,255,0.1);
}

.season-spring .tile-inner { background-color: #005826; border-color: #005826; } 
.season-summer .tile-inner { background-color: #06D6A0; border-color: #06D6A0; } 
.season-autumn .tile-inner { background-color: #f8ab1f; border-color: #f8ab1f; } 
.season-winter .tile-inner { background-color: #ffffff; border-color: #ffffff; } 

.tile-building {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transform: none; /* 회전 제거 */
    pointer-events: none;
    z-index: 2;
}

/* 인트로 모드 시 숫자 숨김 */
.intro-mode .tile-value {
    display: none;
}

.tile-value {
    position: absolute;
    bottom: 5px;
    right: 5px; /* 표준 우하단 배치 */
    background: rgba(13, 17, 23, 0.8);
    backdrop-filter: blur(4px);
    color: white;
    font-size: 0.75rem;
    font-weight: 800;
    padding: 2px 6px;
    border-radius: 4px;
    line-height: 1;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 2px 5px rgba(0,0,0,0.4);
    pointer-events: none;
    font-family: 'Outfit', sans-serif;
    
    transform: none; /* 회전 제거 */
    z-index: 10;
}

.tile-joker .tile-value {
    background: rgba(255, 215, 0, 0.9);
    color: #000;
    border-color: #ffd700;
}

/* 개별 이미지 매핑을 .tile-building 레이어로 이동 */
.tile-2 .tile-building { background-image: url('resource/building/01.png'); }
.tile-4 .tile-building { background-image: url('resource/building/02.png'); }
.tile-8 .tile-building { background-image: url('resource/building/03.png'); }
.tile-16 .tile-building { background-image: url('resource/building/04.png'); }
.tile-32 .tile-building { background-image: url('resource/building/05.png'); }
.tile-64 .tile-building { background-image: url('resource/building/06.png'); }
.tile-128 .tile-building { background-image: url('resource/building/07.png'); }
.tile-256 .tile-building { background-image: url('resource/building/08.png'); }
.tile-512 .tile-building { background-image: url('resource/building/09.png'); }
.tile-1024 .tile-building { background-image: url('resource/building/10.png'); }
.tile-2048 .tile-building { 
    background-image: url('resource/building/11.png'); 
    box-shadow: none; /* 컨테이너로 이동 권장 */
}
.tile-2048 .tile-inner {
    box-shadow: 0 0 25px rgba(35, 134, 54, 0.6), 0 8px 0 #1b6529;
    border: 2px solid var(--accent);
}
.tile-4096 .tile-building { background-image: url('resource/building/12.png'); }
.tile-8192 .tile-building { background-image: url('resource/building/13.png'); }
.tile-16384 .tile-building { background-image: url('resource/building/14.png'); }
.tile-32768 .tile-building { background-image: url('resource/building/15.png'); }
.tile-65536 .tile-building { background-image: url('resource/building/16.png'); }
.tile-131072 .tile-building { background-image: url('resource/building/17.png'); }

/* 조커 매핑 */
.tile-joker .tile-building { 
    background-image: url('resource/building/18.png'); 
}
.tile-joker .tile-inner {
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.8), 0 8px 0 #b8860b;
    border: 2px solid #ffd700;
}

/* 이동 효과: 표준 평면 축에 맞게 스케일 조정 */
.tile-move-up { transform: translateY(-5px) scale(0.98); }
.tile-move-down { transform: translateY(5px) scale(0.98); }
.tile-move-left { transform: translateX(-5px) scale(0.98); }
.tile-move-right { transform: translateX(5px) scale(0.98); }

/* 애니메이션 */
.tile-new .tile-inner {
    animation: appear 200ms ease;
}

.tile-merged .tile-inner {
    z-index: 20;
    animation: pop 300ms cubic-bezier(0.175, 0.885, 0.32, 1.5);
}

.tile-merged .tile-building {
    animation: buildingEvolve 400ms ease-out forwards;
}

@keyframes buildingEvolve {
    0% { transform: scale(1); filter: brightness(1) contrast(1); }
    30% { transform: scale(1.15); filter: brightness(1.8) contrast(1.2) drop-shadow(0 0 15px rgba(255,255,255,0.8)); }
    100% { transform: scale(1); filter: brightness(1) contrast(1); }
}

/* 진화 시 오라 효과 */
.tile-merged::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255,215,0,0.4) 0%, rgba(255,215,0,0) 70%);
    transform: translate(-50%, -50%) scale(0);
    animation: auraEffect 500ms ease-out;
    pointer-events: none;
    z-index: 1;
}

@keyframes auraEffect {
    0% { transform: translate(-50%, -50%) scale(0); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(2.5); opacity: 0; }
}

/* 새로운 레벨 달성 시 발견(Discovery) 효과 - 주석 처리됨 (황금 파티클 폭죽만 유지)
.tile-discovery .tile-inner {
    z-index: 100 !important;
    animation: discoveryPop 800ms cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
    border-color: #ffd700 !important;
}

@keyframes discoveryPop {
    0% { transform: scale(1); filter: brightness(1) contrast(1); box-shadow: 0 4px 15px rgba(0,0,0,0.4); }
    30% { transform: scale(1.4); filter: brightness(2.5) contrast(1.5); box-shadow: 0 0 50px rgba(255, 215, 0, 1); }
    100% { transform: scale(1); filter: brightness(1) contrast(1); box-shadow: 0 4px 15px rgba(0,0,0,0.4); }
}
*/

/* 황금 파티클 폭죽 */
.discovery-particle {
    position: absolute;
    width: 6px;
    height: 6px;
    background: radial-gradient(circle, #fff700 0%, #ffd700 100%);
    border-radius: 50%;
    pointer-events: none;
    z-index: 2000;
    box-shadow: 0 0 10px #ffd700, 0 0 20px #ffaa00;
}

@keyframes particleBurst {
    0% { transform: translate(-50%, -50%) scale(1); opacity: 1; filter: brightness(2); }
    100% { transform: translate(var(--tx), var(--ty)) scale(0); opacity: 0; filter: brightness(1); }
}

/* 계절별 날씨 효과 */
.weather-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
    z-index: 5;
}

/* 벚꽃 (봄) */
.petal {
    position: absolute;
    background: #ffb7c5;
    border-radius: 150% 0 150% 0;
    opacity: 0.8;
}

@keyframes blossomFall {
    0% { transform: translateY(-10vh) translateX(0) rotate(0deg); }
    100% { transform: translateY(110vh) translateX(100px) rotate(450deg); }
}

/* 햇살 & 먼지 (여름) */
.sun-ray {
    position: absolute;
    top: -50%;
    left: -20%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 10% 10%, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 50%);
    animation: rayPulse 4s ease-in-out infinite;
}

@keyframes rayPulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.7; }
}

.dust {
    position: absolute;
    background: rgba(255,255,255,0.4);
    border-radius: 50%;
}

@keyframes dustFloat {
    0%, 100% { transform: translate(0, 0); opacity: 0; }
    50% { transform: translate(20px, -20px); opacity: 0.4; }
}

/* 낙엽 (가을) */
.leaf {
    position: absolute;
    border-radius: 50% 0 50% 0;
}

@keyframes leafFall {
    0% { transform: translateY(-10vh) translateX(0) rotate(0deg); }
    100% { transform: translateY(110vh) translateX(-50px) rotate(720deg); }
}

/* 눈 (겨울) */
.snowflake {
    position: absolute;
    background: white;
    border-radius: 50%;
    filter: blur(1px);
}

@keyframes snowFall {
    0% { transform: translateY(-10vh) translateX(0); }
    100% { transform: translateY(110vh) translateX(20px); }
}

/* 메시지 오버레이 */
.game-message {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(13, 17, 23, 0.85);
    backdrop-filter: blur(8px);
    display: none; /* 기본 숨김 */
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 100;
    text-align: center;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.message-content h2 {
    font-size: 3rem;
    font-family: 'Outfit', sans-serif;
    margin-bottom: 10px;
    color: var(--accent);
}

.message-content p {
    color: var(--text-dim);
    margin-bottom: 20px;
}

.final-score {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 30px;
}

.message-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
}

#share-final-button {
    background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(26, 115, 232, 0.3);
    padding: 12px 25px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 8px;
}

#share-final-button:hover {
    background: linear-gradient(135deg, #1b7cf6 0%, #1565c0 100%);
    box-shadow: 0 6px 20px rgba(26, 115, 232, 0.5);
    transform: scale(1.05);
}

/* 이벤트 메시지Toast */
.event-message-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 200;
    width: 100%;
    text-align: center;
}

.event-toast {
    background: rgba(35, 134, 54, 0.9);
    color: white;
    padding: 15px 30px;
    border-radius: 50px;
    font-weight: 800;
    font-size: 1.5rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    display: inline-block;
    animation: toastUp 1s ease-out forwards;
    white-space: nowrap;
}

@keyframes toastUp {
    0% { transform: translateY(50px) scale(0.5); opacity: 0; }
    20% { transform: translateY(0) scale(1.1); opacity: 1; }
    80% { transform: translateY(-50px) scale(1); opacity: 1; }
    100% { transform: translateY(-100px) scale(0.8); opacity: 0; }
}

.combo-toast {
    background: rgba(255, 165, 0, 0.8) !important;
    font-size: 1.2rem !important;
}

.game-info strong {
    color: var(--text-main);
}

.bgm-info {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.05);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--accent);
    margin-bottom: 12px;
    border: 1px solid rgba(35, 134, 54, 0.2);
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    user-select: none;
}

.bgm-info:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(35, 134, 54, 0.8);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.bgm-info svg {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 0.6; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
    100% { opacity: 0.6; transform: scale(1); }
}

/* 앱 설치 컨테이너 및 버튼 */
.install-container {
    margin-top: 30px;
    display: flex;
    justify-content: center;
    width: 100%;
}

.install-btn {
    background: linear-gradient(135deg, #238636 0%, #2ea043 100%);
    color: white;
    padding: 12px 24px;
    font-size: 1rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(35, 134, 54, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.1);
    animation: bounceIn 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.install-btn:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 6px 20px rgba(35, 134, 54, 0.6);
    cursor: pointer;
}

.install-btn svg {
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

@keyframes bounceIn {
    0% { transform: scale(0.3); opacity: 0; }
    50% { transform: scale(1.05); opacity: 1; }
    70% { transform: scale(0.9); }
    100% { transform: scale(1); }
}

/* iOS 설치 안내 가이드 */
.guide-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(10px);
    z-index: 2000;
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeIn 0.3s ease;
}

.guide-content {
    background: #161b22;
    width: 90%;
    max-width: 340px;
    padding: 30px;
    border-radius: 24px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    text-align: center;
    animation: slideUp 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes slideUp {
    from { transform: translateY(50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.guide-header h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.6rem;
    color: #f0f6fc;
    margin-bottom: 8px;
}

.guide-header p {
    color: #8b949e;
    font-size: 0.95rem;
    margin-bottom: 25px;
}

.guide-steps {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.guide-step {
    display: flex;
    align-items: center;
    gap: 15px;
    text-align: left;
    background: rgba(255, 255, 255, 0.03);
    padding: 15px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.step-icon {
    background: rgba(35, 134, 54, 0.2);
    color: #3fb950;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.guide-step p {
    font-size: 0.95rem;
    color: #c9d1d9;
    line-height: 1.4;
}

.guide-step strong {
    color: #3fb950;
}

.close-btn {
    background: #30363d;
    color: #f0f6fc;
    padding: 12px 0;
    width: 100%;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

.close-btn:hover {
    background: #3fb950;
}

/* 반응형 */
@media (max-width: 450px) {
    .game-board-wrapper {
        width: 320px;
        height: 320px;
    }
    .grid-container, .tile-container {
        gap: 10px;
    }
    .tile {
        width: calc((100% - 30px) / 4);
        height: calc((100% - 30px) / 4);
    }
    .logo { font-size: 1.5rem; }
}

/* 모바일 대응 */
@media (max-width: 480px) {
    .game-board-wrapper {
        width: 320px;
        height: 320px;
    }

    .logo {
        font-size: 1.5rem;
    }

    .score-box {
        padding: 5px 10px;
        min-width: 60px;
    }
}