/* [New] Bottom Sheet for Mode Selection */
.bottom-sheet-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    z-index: 10000;
    display: none;
    align-items: flex-end;
    /* Bottom alignment */
    justify-content: center;
    backdrop-filter: blur(0px); /* [V2] 애니메이션 중에는 렌더 생략 */
    -webkit-backdrop-filter: blur(0px);
    opacity: 0;
    transition: opacity 0.3s ease, backdrop-filter 0.3s ease;
}

.bottom-sheet-overlay.active {
    display: flex;
    opacity: 1;
    backdrop-filter: blur(5px); /* [V2] 안착 완료 후 블러 발동 */
    -webkit-backdrop-filter: blur(5px);
    transition: opacity 0.3s ease, backdrop-filter 0.3s ease 0.15s;
}

.bottom-sheet {
    width: 100%;
    max-width: 500px;
    /* Mobile width constraint */
    background: rgba(20, 20, 25, 0.95);
    border-top-left-radius: 20px;
    border-top-right-radius: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.5);
    padding: 20px 20px 40px 20px;
    transform: translateY(100%);
    transition: transform 0.3s cubic-bezier(0.1, 0.7, 0.1, 1);
    display: flex;
    flex-direction: column;
    gap: 15px;
    /* Removed margin-top: auto and max-height to revert to original behavior */
}

.bottom-sheet-overlay.active .bottom-sheet {
    transform: translateY(0);
}

.sheet-header {
    text-align: center;
    font-size: 16px;
    font-weight: bold;
    color: #fff;
    margin-bottom: 5px;
    position: relative;
    padding-bottom: 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sheet-header::before {
    /* Drag Handle */
    content: '';
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 2px;
}

.mode-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.05);
    cursor: pointer;
    transition: all 0.2s ease;
}

.mode-card:active {
    transform: scale(0.98);
    background: rgba(255, 255, 255, 0.1);
}

.mode-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    flex-shrink: 0;
}

.mode-info {
    flex: 1;
}

.mode-title {
    font-size: 16px;
    font-weight: bold;
    color: #fff;
    margin-bottom: 4px;
}

.mode-desc {
    font-size: 12px;
    color: #aaa;
    line-height: 1.3;
}

/* Specific Modes */
.mode-survival .mode-icon {
    background: rgba(255, 59, 48, 0.15);
    color: #ff3b30;
    box-shadow: 0 0 10px rgba(255, 59, 48, 0.2);
}

.mode-training .mode-icon {
    background: rgba(52, 199, 89, 0.15);
    color: #34c759;
    box-shadow: 0 0 10px rgba(52, 199, 89, 0.2);
}

.sheet-close-btn {
    width: 100%;
    padding: 15px;
    background: transparent;
    border: none;
    color: #888;
    font-size: 14px;
    margin-top: 5px;
    cursor: pointer;
}