:root {
    --neon-blue: #6366f1;
    --neon-green: #10b981;
    --bg-light: #f8fafc;
    --panel-white: #ffffff;
    --text-main: #1e293b;
    --border-color: #e2e8f0;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-light);
    font-family: 'Orbitron', sans-serif;
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
}

/* 뷰 컨테이너 공통 */
.view-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--panel-white);
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.05);
    width: 320px;
    border: 1px solid var(--border-color);
}

/* 로고 애니메이션 */
.logo-area img {
    width: 140px;
    height: auto;
    border-radius: 20px;
    transition: transform 0.3s ease;
}
.logo-area img:hover {
    transform: scale(1.05) rotate(2deg);
}

/* 입력창 */
input {
    width: 100%;
    padding: 12px;
    margin-bottom: 12px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-family: 'Orbitron';
    box-sizing: border-box;
    outline: none;
    transition: border-color 0.2s;
}
input:focus {
    border-color: var(--neon-blue);
}

/* 버튼 공통 */
.main-btn {
    width: 100%;
    padding: 15px;
    border: none;
    border-radius: 12px;
    font-weight: 900;
    cursor: pointer;
    font-family: 'Orbitron';
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.main-btn:active {
    transform: scale(0.97);
}

/* 싱글 게임 카드 스타일 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-top: 20px;
}

.card {
    aspect-ratio: 1 / 1;
    background: #e2e8f0;
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 900;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.card.hidden {
    background: var(--neon-blue);
    color: transparent;
}

.card.flipped {
    background: white;
    border: 2px solid var(--neon-blue);
}